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neutriNote: Markdown with Math in Just 3 MB!

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User Guide

[Japanese Edition]

Table of Contents

  1. Getting Started
  2. Backup and Restore
  3. Mirror
  4. Search Tools
  5. Advanced Features
  6. Performance
  7. Log Tool
  8. Encryption
  9. OCR
  10. Relocate Local Repository
  11. Known Issues
  12. FAQs
  13. Privacy Policy
  14. TODO
  15. Source Code
  16. About

Getting Started

Thank you for choosing neutriNote.

Right after installation, be sure to follow the onscreen instruction and choose a location for Local Repository.

If your repository is empty, you may add notes right away.

If you have installed neutriNote previously, you may pick the repository already on your device.

If you have settings backed up from your previous installation, you may also choose Restore App Data to restore settings.

To enable sync is easy, either install a third party app like Syncthing and register your repository with it or get neutriNote Connector+ – a Dropbox adapter designed just for neutriNote.

Even without add-ons, neutriNote is ready for use. Explore around to discover many features that would make neutriNote a highly integrated part of your note taking experience (for example, long tap metadata label to retrieve notes sharing similar label and tap the local find icon in the edit screen to jump to the next match). To extend it into a tool for personal information management, please do take a moment to go over the following sections. New users may also want to check out Backup and Restore for ways to preserve note data beyond the sync mechanism.

IMPORTANT: from v1.3.1, neutriNote supports Runtime Permissions in Android Marshmallow devices. Be sure to grant neutriNote permission to access external storage for its Local Repository to work properly. To enable previously denied permissions, go to neutriNote’s App Info under Android, renable the permissions and restart the app.

Backup and Restore

If you have already activated Local Repository, your notes will be sync seamlessly to the repository. You can replicate your notes remotely by sharing the folder with third party apps such as Syncthing. IMPORTANT: Do NOT use stale repositories since they could be out of sync. Always use the method described in the Getting Started section from above to initialize and assign repositories.

Incremental Backup is another way to copy your notes in non-intrusive fashion. To enable, simply do so from Settings. Then your notes and app settings will be backed up incrementally at least once daily to a internal storage folder called neutrinote_export. Note: exported app settings data are stored in regular notes with prefix .neutrinote so that they can be sync no differently from other notes.

When incremental backup is enabled, a task to conduct full backup when the device is idle will also be activated. A maximum of 10 most recent backups will be maintained. See Storage Saver section for more suggestions on how to manage backup storage space.

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Mirror (v3.3.1 or above)

Mirror is a replica of Local Repository much like a Remote Repository for push and pull local and remote changes. The primary difference between Local Repository and Mirror is that in Android 11 access to the former is restricted for privacy reasons, while the later is accessible to 3rd party apps, such as peer-to-peer sync or a secondary text editor. Thus Mirror is offered as an option depending on your privacy preferences and workflow. To activate the feature, simply add a folder under backup folder and name it mirror, Mirror Files will appear under the main note list menu with options to push and pull changes.

Note that only deletions initiated from neurtiNote (i.e. Local Repository) will be mirrored.

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Search Tools

While notes can be retrieved based on modified time, accessed time, and location as providied by the user interface, neutriNote supports high precision text based search and regular expression. The syntax below are also highly reusable when they are included as part of the preset filters (under Settings).

Search by Fields It is possible to restrict search to a specified field. For example, at the main search bar over the note list, search can be limited to titles by using the prefix title: in the search string. A search string liketitle:log will return all notes with the substring log in the titles. To apply regular expression in title search, use the prefix titlereg:.

Search can also be limited to metadata by using the prefix meta: in the search string. A search string such as meta:personal will return all notes with the substring personal in the metadata (likewise meta: will return notes without metadata). It is also possible to use regular expression in metadata search, simply use the prefix metareg: in the search string.

To ensure metadata match when conducting multi-term search, one may use the following syntax at the main search bar: join:term1,term2,term3,...,termN and so on. Doing so will ensure at least one of the terms can be found in the metadata for each search hit. Such syntax can be used to simulate search within metadata/tags. Alternatively, fuzzy search can be conducted on metadata with syntax related:term1,term2,term3,...,termN and similar:term1,term2,term3,...,termN.

To search for multiple terms, the easiest way is to use Advanced Search. You can also specify boolean search queries with syntax like and:term1,term2,term3,...,termN to find notes containing all the terms (or:term1,term2,term3,..,termN to find notes containing one of the terms).

Custom Filters The power of the above syntax lies in that it can also be included in preset search filters so that users can easily deploy. Custom filters can be specified in Settings delimited by semi-colons. They are defaulted to be:


all is reserved for retrieving all notes, and starred reserved for retrieving starred notes. Single character filters are reserved for retrieving notes with titles beginning with said alphabets.

For searching within notes, neutriNote recognizes basic Perl style patterns: \d for digits, \s for whitespace, etc.

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Advanced Features


Metadata are general purpose text strings that exist outside note data. They are searchable and can be used as tags. To emulate filtering by tags, simply enter into the main search bar queries like tag:term1,term2,term3,...,termN, so that each term must be present in the metadata (in any order) for a note to be considered a match. On the other hand, if the presence of any one term is sufficient for a note to be considered a match, use tag*:term1,term2,term3,...,termN instead.

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neutriNote supports PHP Markdown Extra and LaTeX style mathematical expressions. The easiest way to enter mathematical expressions is to wrap them in $$. For inline math, use \\(...\\) as in the example below:

This expression \\(\sqrt{3x-1}+(1+x)^2\\) is an example of an inline equation.

To create in-document anchors/footnotes in PHP Markdown, use link syntax as in the following example:

# heading 1 {#header1}

## heading 2

* item 1:
    + sub item *1.1*
    + sub item *1.2*
* item 2
    + sub item *2.1*
    + sub item *2.2*
    + sub item 
    + [Link back to header 1](#header1)

To allow table of contents to be generated automatically, add a placeholder <span id='toc' />, tag each paragraph header with a unique ID by following the convention of PHP Markdown special attributes such as{#id}. Try the example below:

Table of Contents

<span id='toc' />

## Header 1 {#header1}
    * Your paragraph here...
## Header 2 {#header2}
    * Your paragraph here...
## Header 3 {#header3}
    * Your paragraph here...

To create link between notes, simply use one of the following syntax (%20 denotes space):

[My File](file:///sdcard/neutriNote/my_file.txt)

[My File](./my_file.txt)

[My File](my_file.txt)


Linking to an image under local repository, simply do:

![My Image](my_image.jpg)

Linking to notes from other apps that support hyperlinks, simply prefix note names with For example:

There is a conflict between Markdown italic symbol and LaTeX subscript symbol. To workaround this problem, either escape the subscript symbols or wrap the expression in script block. For example, instead of doing this:

$$k_{n+1} = n^2 + k_n^2 - k_{n-1}$$

do this:

$$k\_{n+1} = n^2 + k\_n^2 - k\_{n-1}$$

Or use script block with the desired type like this:

<script type="math/tex">k_{n+1} = n^2 + k_n^2 - k_{n-1}</script>

On the other hand, to allow line breaks within $$ segments, use \\\ instead of \\.

It’s easy to customize the style of Markdown with popular inline CSS. For more extensive styling needs, you can “swap out” built-in styling by declaring your CSS in ~neutrinote_styles.txt. If your style is based off an existing Markdown theme, this process is pretty much effortless. For example, to solarize your Markdown, simply copy and paste the following two lines into ~neutrinote_styles.txt.

<link href="" rel="stylesheet"></link>
<script src=""></script>

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An example of how neutriNote’s rendering component could be used to plot a graph using JSXGraph:

<div id="box" class="box" style="width:500px; height:500px;"></div>
<script type='text/javascript' src=''></script>
<script type='text/javascript'>
 var b = JXG.JSXGraph.initBoard('box', {boundingbox: [-10, 10, 10, -10], axis:true});
b.create('functiongraph', [function(x){return Math.sin(x);},-Math.PI,2*Math.PI]);

An example of how neutriNote’s rendering component could be used to draw a simple shape:

<canvas id="example" width="200" height="200">

var example = document.getElementById('example');
var context = example.getContext('2d');
context.fillStyle = 'red';
context.fillRect(30, 30, 50, 50);

Draw a simple diagram in plain text is easy using yUML. Try this (note the single ticks):

<img src="[Cms Admin]^[User], [Customer]^[User], [Agent]^[User]" >

<img src="`[Customer]->[Billing Address]`">

Tabular data can be processed by custom codes (note the placeholder cells for outputs):

| Type A | Type B | Type C |
|       1|       2|       3|
|       2|       2|       4|
|       3|       2|       5|
|        |        |        |

            $('table thead th').each(function(i)

        function sumCol(index)
            var total = 0;
            $('table tr').each(function()
                var value = parseInt($('td', this).eq(index).text());
                if (!isNaN(value))
                    total += value;
            $('table tr:last td').eq(index).text('Total: ' + total);

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neutriNote can easily be integrated into existing Tasker automation. For example, to launch a third party Tasker plugin, it can be as simple as creating a Tasker profile to “observe” Local Repository events. Specifically, to trigger third party sync plugins, simply add a blank file ~neutrinote_noop.txt in Local Repository and have its modifications monitored by Tasker to piggyback a modification event corresponding to that file emitted by pull-to-refresh in neutriNote.

One of the most useful features of Tasker is its rich set of variables. One can easily maintain of log of the variables in neutriNote as well. Consider this example of keeping clipboard history in neutriNote: simply create a profile to monitor the setting of Tasker’s %CLIP variable, then add the following task (replace the path with that of your Local Repository):

A1: Variable Set [ Name:%NEWLINE To:Do Maths:Off Append:Off ] 
A2: Write File [ File:neutriNote/clipboard_events.txt Text:## %DATE %TIME %NEWLINE %CLIP %NEWLINE Append:On Add Newline:On ] If [ %clip neq %clip_prev ]
A3: Variable Set [ Name:%clip_prev To:%CLIP Do Maths:Off Append:Off ] 

Combined with other ways to extend neutriNote, there are essentially an infinite number of ways to automate the creation of richer note contents.

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Text Expansion

neutriNote supports text expansion: simply highlight any shortcut word and tap the Text Expansion icon to expand the word. All shortcuts are saved in a file called ~neutrinote_shortcuts, with one definition per line in the format of shortcut label|expanded text (if you do not see the file, enable hidden files under Settings). Below are some examples:


# Usage: select "highlight your_text" and expand, return "<mark>your_text</mark>".

Shortcuts can be defined for frequently used patterns for string replacements. For example:

# Usage: select "encode some_text_string" and expand, some_text_string will be returned with all blank spaces encoded.
encode|neutriNote#replace \s %20

To replace all occurrences of a specific pattern by line breaks, simply:

# Usage: select "eol some_text_string" and expand, some_text_string will be returned with all blank spaces replaced by linebreaks.
eol|neutriNote#linebreak \s

To join multiple lines, try using this:

# Usage: select "join some_text_string" and expand, some_text_string will be returned with all newline characters replaced by blank spaces.
join|neutriNote#replace \n \s

Or even this:

# Usage: select "concat some_text_string" and expand, some_text_string will be returned with all lines concatenated.
concat|neutriNote#remove \n

<nano:br> can also be used as placeholders for linebreaks in shortcut definitions. For example:

# Create a blank 3x2 table.

3x2|| | | |<nano:br>|---|---|---|---|<nano:br>| | | |<nano:br>|---|---|---|---|

An example to trim leading and trailing spaces from a body of text:

# Usage: select "trim some_text_string" and expand, leading and trailing spaces of some_text_string will be removed.

Shortcuts to obfuscate / defuscate a chunk of text:

# Usage: select "obfuscate some_text_string" and expand, some_text_string will be obfuscated.

# Usage: select "defuscate some_text_string" and expand, some_text_string will be defuscated.

You can also use basic C style format specifiers to “morph” text snippets.

# Usage: select "addcomma some_numeric_string" and expand, some_numeric_string will be comma separated.
addcomma|neutriNote#morph ℅,d

These simple shortcuts make it easy to sort lines:

# Usage: select "sort some_lines" and expand, some_lines will be sorted.

# Usage: select "rsort some_lines" and expand, some_lines will be sorted in reverse order.

There is even a way to remove HTML tags from strings:

# Usage: select "notag some_text_string" and expand to remove HTML tags from some_text_string.

To remove zero-width spaces, simply do:

# Usage: select "zero some_text_string" and expand to remove zero-width spaces from some_text_string.

You can create shortcuts for simple shell commands as well. Give it a try by adding the prefix neutriNote$ to the commands just like below:

date|neutriNote$ date
ps|neutriNote$ ps

To emulate the behavior of to-do list, shortcuts can be defined to mimic checkbox toggling.

# Usage: place cursor next to any asterisk and expand.  To toggle checkboxes, tap expand again.


Multitasking especially with floating apps is easier with shortcut like this:

# Usage: launch a terminal without leaving neutriNote by expanding the shortcut.

termfloat|neutriNote#launch com.termux.window

Open a note directly from the current note with this:

# Usage: jump directly from one note to another by creating a "funnel."


Quickly sift through the entire repo for a selected term:

# Usage: select "fetch some_text_string" and expand to look up some_text_string throughout the repo.


Or issue canned searches like this:

# My favorite constant

fetch_pi|neutriNote#needle 3.141592653589793

The following shortcut allows you to create a link to the current note, at the position of the currently selected text:

# Usage: select "link some_text_string" and expand to create in clipboard a link to the current note at the position of the selected text.  A link from other notes to this note can then be created by pasting the current clipboard content into other notes.


You can include basic parameters with the commands, just write them after the command shortcut and separate each parameter with space+commas like this: shortcut_label param1 , param2 , param3. Select the whole string and tap the expand icon to paste the output. Users of cURL can also simplify the definitons of their expansions with neutriNote? instead of neutriNote$ and trail that directly by a URL.

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Batch Select

Special selection commands are available for better productivity.

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Voice Memo

neutriNote is compatible with Google Now dictation. Simply say Ok Google note to self and pick neutriNote to capture what you say.

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External Fonts

It’s easy to use external fonts such as those featured by Google Fonts in neutriNote (IMPORTANT: be sure to read their terms of use carefully):

  1. Create a folder called fonts under your Local Repository, download and save the font file (.ttf) in that folder. Note that external fonts will not be backup by neutriNote.
  2. Enable hidden files under Settings. Create a new note called ~neutrinote_fonts if one does not exist yet.
  3. Add a section in the note for the font (if there are multiple fonts, separate each section by a blank line) with a line dedicated to each of the following:
    • Font name (any meaningful name)
    • Font file name (.ttf)
    • Link information (see instructions from Google Fonts)
    • CSS style (see instructions from Google Fonts)
  4. The font is now ready for use in neutriNote.

For example, to use this font, just add this section to ~neutrinote_fonts:

Goudy Bookletter 1911
<link href='' rel='stylesheet' type='text/css'>
font-family: 'Goudy Bookletter 1911', serif;

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Ambient Glow

Ambient Glow is an experimental function that adjusts the color temperature of neutriNote to approximate the level of your current environment for a more atmospheric editing experience. It differs from blue light filtering apps in that it does not demand your location information – instead only light sensor data from Tasker will be used (to conserve battery). neutriNote Auto Theme is required for this function to work properly. Note that Ambient Glow will not be applied to Markdown and for users of blue light filters it is recommended that this function be disabled.

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The following editor shortcuts are supported when connected to a physical keyboard:

Shortcuts Actions
Ctrl-S Save
Ctrl-F Local Find
F3 Find Next
Ctrl-H Replace
Ctrl-D Dictionary Lookup
Ctrl-W Web Search
Ctrl-M Markdown
Ctrl-Z Undo
Ctrl-Shift-Z Redo
Ctrl-] or Ctrl-I Indent
Ctrl-[ or Ctrl-Shift-I Un-indent

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Various user interface elements support gestures for better productivity:

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What follows are features that may conflict with the core functions of neutriNote. Use at your own discretion.

You can tinker with the variables found inside of ~neutrinote_settings_data (enabled by Show Hidden under Settings). After saving your changes, do Restore App Data for the changes to take effect. Note: altering the setting file could affect the stability of neutriNote.

Variable Names Values
com.appmindlab.nano.pref_append_custom_style true: Extend built-in styles with ~neutrinote_styles.txt, false: Replace built-in styles with ~neutrinote_styles.txt
com.appmindlab.nano.pref_auto_toolbar_tag Specify a metadata substring pattern to enable auto show / hide toolbar (hint: tap screen to hide, double tap to re-display)
com.appmindlab.nano.pref_canvas_strokes Fixed width symbols supported by sketch tool delimited by semicolons, e.g., :;\;/;_;-;,;● (vertical bar and semicolon not allowed)
com.appmindlab.nano.pref_custom_date_format Override system date stamp format with custom date format
com.appmindlab.nano.pref_custom_time_format Override system time stamp format with custom time format
com.appmindlab.nano.pref_eval_built_in_variables true: evalute built-in variables in search or shortcut definitions
com.appmindlab.nano.pref_excluded_buttons Selectively hide toolbar buttons via a semicolon delimited string, e.g., location;draw;replace will hide the location, draw, and replace buttons on the toolbar. The following buttons can be hidden: markdown, time, date, location, expand, draw, top, bottom, find, replace, barcode, image, ocr, define, calculate, search, encrypt, decrypt
com.appmindlab.nano.pref_font_size_list Specify custom font size options delimited by semicolons. Default: 8;10;12;14;16;18;24;32;48
com.appmindlab.nano.pref_icon_behavior 0: animation off, 1: animation on, 2: snooze animation
com.appmindlab.nano.pref_indent_char Specify the character(s) to use for indentation. Default: 4 spaces
com.appmindlab.nano.pref_keep_deleted_copies true: keep copies of deleted files under trash_bin folder
com.appmindlab.nano.pref_lab_mode true: enable experimental features such as OCR, diff-tool
com.appmindlab.nano.pref_latex_single_dollar true: use single dollar signs to signify math expressions
com.appmindlab.nano.pref_linkify_trigger Specify a metadata substring pattern to open notes linkified by default
com.appmindlab.nano.pref_local_priority_tag Specify a metadata substring pattern to prevent local copy from being overwritten by remote changes. Note that conflicts may occur if a note is being edited on multiple devices
com.appmindlab.nano.pref_low_space_mode true: turn on storage space saver
com.appmindlab.nano.pref_margin_list Specify custom margin options delimited by semicolons. Default: 8;16;24
com.appmindlab.nano.pref_markdown_trigger Specify a metadata substring pattern to open notes in Markdown by default
com.appmindlab.nano.pref_max_deleted_copies_age Specify maximum number of days deleted copies will be kept (pruning to occur during next backup). Default: -1 (unlimited)
com.appmindlab.nano.pref_max_sync_log_file_age Specify maximum number of days sync logs will be kept. Default: 7 (1 week)
com.appmindlab.nano.pref_max_sync_log_file_size Specify maximum size for each sync log file (factor of 200 KB). Default: 2 (400 KB)
com.appmindlab.nano.pref_new_note_file_type Specify file type for new notes. Multiple type mode required (see below). Default: .txt
com.appmindlab.nano.pref_new_note_title_template Specify title template for new notes. Default: New Note
com.appmindlab.nano.pref_oled true: dim screen elements for OLED screens
com.appmindlab.nano.pref_open_in_markdown true: always open notes in markdown preview
com.appmindlab.nano.pref_parse_python true: enable basic Python code interpretation. Default: false
com.appmindlab.nano.pref_parse_vue true: enable basic Vue.js components. Default: false
com.appmindlab.nano.pref_preview_mode start: display the beginning of notes in preview, end: display the end, off: disable preview
com.appmindlab.nano.pref_process_text_mode 0: disabled, 1: allow paste from other apps, 2: allow search from other apps . Default: 0
com.appmindlab.nano.pref_remote_priority_tag Specify a metadata substring pattern to override local changes with remote changes when they occurred concurrently. Note that conflicts may occur if a note is being edited on multiple devices
com.appmindlab.nano.pref_safe_mode_tag Specify a metadata substring pattern to disable internal Markdown parser
com.appmindlab.nano.pref_show_toolbar true: always show edit toolbar (hint: tap screen to hide, double tap to re-display)
com.appmindlab.nano.pref_star_at_top true: place starred notes above other notes in list view. Default: false
com.appmindlab.nano.pref_toolbox_mode stateful: keep editor toolbox scroll position (default), stateless: always reset editor toolbox scroll position, pin_save: keep save button visible
com.appmindlab.nano.pref_working_set_size Specify size of working set (the set of recently accessed notes). Default: 6

Advanced users may enable multiple text file types for neutriNote. To setup, please carefully follow all the steps below:

  1. Backup ALL app settings and notes.
  2. Add a blank file called ~neutrinote_multitype.txt to your Local Repository.
  3. Un-install neutriNote (or clear the app’s data under Android’s system settings).
  4. Re-install neutriNote.
  5. Once rescan finishes, file extensions will appear in note titles.
  6. Restore app data.

(To reverse the support of multiple file types, you would need to remove the file ~neutrinote_multitype.txt, then un-install/re-install neutriNote.)

To enable search history transfer across devices, simply add a note called ~neutrinote_search_history.txt. Search history can then be cloned when app data are restored by tapping Restore App Data on your other devices.

Note that neutriNote Connector will not handle files without .txt extension. To sync files without .txt extension with Dropbox you would have to install a third party app or install neutriNote Connector+. (If you have neutriNote Connector installed, you would need to remove it prior to launching neutriNote Connector+. If you have neutriNote Connector+ installed, you would need to re-install the app.)

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Built-in Variables

Built-in variables may be used in search or shortcut definitions. For example, to find notes with tomorrow’s time stamp, simply type @tomorrow in the search box. You can even include built-in variables in Custom Filters, say, for listing notes containing tomorrow’s time stamp, or include them in shortcut definitions to generate text expansion snippets on the fly.

Variables Descriptions
@title Title of the current note.
@created Created time of the current note.
@modified Last modified time of the current note.
@accessed Last accessed time of the current note.
@clipboard Clipboard content.
@yesterday Yesterday’s date stamp.
@today Today’s date stamp.
@tomorrow Tomorrow’s date stamp.
@now Current time stamp.

See Hacks for information on how to enable the use of built-in variables.

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Custom Variables (v3.3.0 or above)

Custom variables are variables with the prefix @@ and are used as shortcuts in conducting local search. Say you have a shortcut defined like this:

# End of Paragraph

Enter @@eop in local search bar and tap search will take you to the boundary of each paragraph. (Indeed a rudimentary tool to overview long notes when combined with gestures.)

Note that only shortcuts defined for simple string replacement are supported.

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Storage Saver

For devices equipped with SD cards, it is possible to store backups on SD cards to save space in internal storage.

  1. Tap Backup App Data.
  2. Add com.appmindlab.nano.pref_low_space_mode|true to ~neutrinote_settings_data.
  3. Tap Restore App Data.
  4. Future backups will be stored at /Android/data/com.appmindlab.nano/files/neutrinote_export under the SD card.

Notice that the backups will be automatically removed to reclaim storage space if neutriNote is uninstalled.

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neutriNote’s Markdown engine is fully modular and swappable. If you are familar with compiler scripting and would like to integrate your own parser, you would need to use the following entry points in your code:

Methods Descriptions
init(document) Initialize the framework.
getData() Get raw content from a note.
prepare() Prepare for the rendering process.
setContent(html) Set view to rendering outcome.

Adopt this pattern of invoking neurtiNote in your script:

(function (){
  // Set up //

  // Get raw data //
  var str = neutriNote.getData();

  // Prepare for rendering //

  // Parse //
  ... <- Custom conversion logic goes here!

  // Set content //

})(window, document);

To illustrate, suppose you simply want to render everything in italics, all you need is to create ~neutrinote_script.txt and paste in the following code:

(function (){
  // Set up //

  // Get raw data //
  var str = neutriNote.getData();

  // Prepare for rendering //

  // Parse //
  str = '<i>' + str + '</i>';

  // Set content //

})(window, document);

Now go to your note and tap render to view the output of your custom parser.

More useful parsing can be achieved by following the same pattern. Take a look at this example of integrating org-mode into neutriNote.

To restore default PHP Markdown syntax, just remove ~neutrinote_script.txt.

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Python Support (Experimental)

neutriNote can evaluate in-note Python code snippets. To enable this feature, simply set Python parsing flag to true as shown under Hacks section.

To see it in action, copy the code below and tap Markdown Preview button:

<script type="text/python">
    from browser import document
    document <= "Hello world !"

A slightly more complex example:

<script type="text/python">
    from browser import document

    # Sort a list
    aList = [5, 8, 7, 6, 2, 3]
    aList = sorted(aList)
    result = '\n'.join(str(i) for i in aList)

    # Print the output
    document <= result

(Note that the script tag is required to indicate the scope of Python code.)

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Web Components

neutriNote supports reusable user defined components through Vue.js. This is especially useful for including frequently used note elements.

To enable, simply enable Vue parsing shown under Hacks section and create a new note with the title app.js and neutriNote will handle the rest.

To see it in action, copy the following sample component definition for <btn-style> to app.js, the file where all component declarations are to be placed:

Vue.component('btn-style', {
    props: ['theme'],
    template: '<li></li>'

var app = new Vue({
    el: '#app',
    data: {
        buttonStyles: [
            { id: 0, desc: 'primary' },
            { id: 1, desc: 'secondary' },
            { id: 2, desc: 'success' },
            { id: 3, desc: 'warning' },
            { id: 4, desc: 'info' }

That’s it! Now see how easy it is to deploy <btn-style> anywhere throughout your notes as long as it is inside a div block by the id app.

<div id="app">
        <btn-style v-for="item in buttonStyles" v-bind:theme="item" v-bind:key=""></btn-style>

Note that currently neutriNote does not support the import of external components, so not a substitute for any full-scale development architecture.

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Text Editor

Though outside the scope of note taking, neutriNote can be used as a lightweight text editor to supplement apps such as Dropbox or Google Drive across all folders. Changes committed will be sent back to original locations of edited files instead of storing in Local Repository, if the files are located outside Local Repository. (Note that files not stored in Local Repository will not be cataloged by neutriNote’s search engine.)

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Snooze (Experimental)

With neutriNote’s non-intrusive visual reminders, it is easy to set aside notes for editing later, or build a habit of reviewing saved notes. Simply enable snooze animation by appending the following to ~neutrinote_settings_data:


Then add special snooze strings such as +1h (“snooze for an hour”) or +2d (“snooze for two days”) to the metadata of selected notes. By doing so a non-intrusive animation will remind you to view the notes if they have not been visited long enough. The visual reminders would be dismissed as soon as the notes were opened. To de-activate the snooze, simply remove the snooze string from the note’s metadata.

Units Examples
m for minutes +30m: snooze for 30 minutes
h for hours +8h: snooze for 8 hours
d for days +3d: snooze for 3 days
w for weeks +2w: snooze for 2 weeks
M for months +3M: snooze for a quarter
y for years +10y: snooze for a decade

To transfer snooze to another device, be sure to tap Backup/Restore App Data. Even more useful is that snooze strings are also fully searchable, they work just like regular metadata!

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neutriNote comes with many goodies for capturing text based data without switching away such as the built-in barcode scanner. Another is a handy calculator for solving mathematical expressions based on Math.js (network connection required). To see how that works, try one of the following examples in your notes:

  1. Select the expression.
  2. Tap the calculator button from the toolbar.
  3. View the answer with the option to paste it back into your note.
sin(45 deg) ^ 2

cos(45 deg)

5.08 cm to inch

det([-1, 2; 3, 1])

log(10000, 10)

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When editing a long note, hide the title bar to reduce lags.

In general, using default font style can help reduce the time in opening long notes.

For users who do not use mathematics expressions, mathematics rendering can be disabled by entering a . under Mathematics in Settings. Markdown rendering should be faster with mathematics disabled.

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Log Tool

neutriNote provides a simple log mechanism to monitor Local Repository changes caused externally. This is useful especially when cross-platform sync is in use. To activate logging, simply add a file called ~neutrinote_sync.log under Local Repository and observe that the log folder will be created automatically to record remote data changes such as inserts, deletes, or in-place updates. Log attributes such as sizes and recycle frequencies can be customized further via pref_max_sync_log_file_age and pref_max_sync_log_file_size settings (see Hacks section).

Note that logging may have impacts on overall performance and battery consumption. To stop recording changes, simply delete ~neutrinote_sync.log.

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Encryption (v3.3.9 or above)

Encryption support in neutriNote is provided via OpenKeyChain which is an open source, independently audited tool. This setup allows your encryption keys to be stored independent of neutriNote.

Assuming OpenKeyChain has been installed, simply follow these steps to encrypt your note content:

  1. Select a section of note that you want encrypted.
  2. Tap the Encrypt button 🔒 under the editor toolbar to launch OpenKeyChain.
  3. Once in OpenKeyChain, either pick an existing key or use a password to encrypt.
  4. Close OpenKeyChain and you will be sent back to the note.
  5. Paste the newly encrypted content in to replace the text selected.

Follow these steps to decrypt a note:

  1. To decrypt, tap anywhere within -----BEGIN PGP MESSAGE----- and -----END PGP MESSAGE-----.
  2. Tap the Decrypt button 🔓 under the editor toolbar to launch OpenKeyChain.
  3. Once in OpenKeyChain, your content will automatically be decrypted.
  4. Pick Copy to clipboard at the menu.
  5. Close OpenKeyChain and you will be sent back to the note.
  6. Paste the newly decrypted content in to replace the text selected.

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OCR is disabled by default. To enable OCR in neutriNote installed from Google Play, simply follow the instructions under Hacks and set com.appmindlab.nano.pref_lab_mode to true. Once done, OCR icon will appear in the tool bar. To enable OCR in neutriNote CE installed from F-Droid, simply install OCR with Tesseract 4 from F-Droid.

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Relocate Local Repository

While generally not recommended, there may come a time when Local Repository has to be relocated. Please handle the following steps with care:

  1. Backup ALL app settings and notes.
  2. For pre-Android 9 devices, copy Local Repository folder to its new location. For Android 9 or above, Local Repository can only be located anywhere under /Android/data/com.appmindlab.nano/files.
  3. Un-install neutriNote (or clear the app’s data under Android’s system settings).
  4. Re-install neutriNote.
  5. Point Local Repository to its new location.
  6. Restore app data.

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Known Issues

Anytime a note is accessed from widget, if there is a note already being edited, the note originally being edited will exit without saving. neutriNote does not distinguish between opening a note from widget or from the note list, the currently opened note will be closed to make way for the newly opened note. It is thus highly recommended that important changes be saved right away.

If a note needs to be renamed, do so within neutriNote. Certain cloud sync would also change the case of note titles. neutriNote would detect those changes and be case insensitive accordingly. However, neutriNote would not delete notes unless their titles match exactly. Therefore it is so crucial that notes be renamed from the end of neutriNote.

To improve app stability in lower-end devices, neutriNote supports note size up to 1.5 MB. Notes beyond the size will automatically be moved to a folder called import_errors. To bring them back into neutriNote, you would need to split the notes into files below 1.5 MB and move them into the repository folder.

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No folder support? neutriNote is designed to provide a flat, hierarchy-free, “low cognitive load” note taking experience so that the number of taps can be minimized, folder navigation would require a nested UI and more taps to get to notes beyond the root level. On top of that, offline search would need to traverse levels of folders in such a way that turnaround time could vary perceivably. Metadata used together with custom filters provides more general organization than folders (a note can match multiple metadata simultaneously).

Story behind the name? This came up when trying to conjure up something that conveys unclutterness.

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Privacy Policy

This app does not gather personal information. Location data can always be disabled via Settings. A menu option is also provided to clear search history.

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Source Code

For further customization, neutriNote’s source code is available on GitHub as Community Edition.

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Keep the app as crash-proof as possible.

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Every effort has been made to ensure that all third-party software used be properly acknowledged (see license information in the About dialog). Please feel free to contact by email anytime should such information be found incomplete or inaccurate.

You can also visit Product Page for development updates regarding the app.

To further support neutriNote’s development, please visit developer’s Ko-fi page.

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