Your e-reader, made of plugins.

PaperPaw is reading software for e-readers. Home screen, reading view, menus, gestures, widgets: change any part with a plugin, or with a folder of text files. No fork, no rebuild.

Download for Android

Version 0.4.0, 7.2 MB, Android 8 or later. Free and open source; no account, no ads, no tracking. Other ways to install

Contents

What PaperPaw does, one chapter each, shown on a device.

  1. 1 Annotations Bookmarks and highlights at the exact place, with notes; exported as Markdown and shared with KOReader. The reading menu, as on a Boox Go 7
  2. 2 Calibre Calibre sends, lists and deletes books over Wi-Fi, as with any wireless reader. The library, as on a Boox Go 7
  3. 3 Colour Covers and pictures in colour on colour e-ink; sixteen crisp greys everywhere else. A plate by Edmund Dulac for The Tempest, in colour, in the emulator, as on a colour e-ink screen
  4. 4 Formats EPUB, FB2, Markdown, plain text, comics and PDF, with hyphenation and footnotes. A page of Pride and Prejudice, as on a Boox Go 7
  5. 5 Gestures Up for home, down for the quick panel, in from a side for back, two fingers for size. The gestures, shown once, as on a Boox Go 7
  6. 6 Home screen A grid as on a phone: clock, current book, recent books and tools, arranged by dragging. The home screen, as on a Boox Go 7
  7. 7 KOReader Reading positions, statistics and annotations travel to and from KOReader. A page of Pride and Prejudice, as on a Boox Go 7
  8. 8 Library Covers and progress, shelves by author, series and tag, a search and OPDS catalogs. The library, as on a Boox Go 7
  9. 9 Lock An optional PIN, pattern or password when the reader wakes up. Setting a PIN, as on a Boox Go 7
  10. 10 Memory On the Xteink X4, an ESP32-C3 with 400 KB of RAM and no PSRAM, PaperPaw runs in a heap of 256 KB; its firmware takes 6.5 MB of the 16 MB of flash. Reading on the smallest device, in the emulator, as on an Xteink X4
  11. 11 Menus Every menu changes on the device: drag entries, remove them, add any action. A menu, rearranged by dragging, as on a Boox Go 7
  12. 12 Plugins Home, library, reading view, menus and themes are plugins; a folder of text files is one too. Plugins, switched on and off, as on a Boox Go 7
  13. 13 Quick panel Night mode, light, rotation, a full refresh and sleep, one swipe from anywhere. The quick panel, as on a Boox Go 7
  14. 14 Rules Night mode at ten, a message when the battery is low; with conditions if you like. Rules, as on a Boox Go 7
  15. 15 Tools Swipe up on the home screen for every tool, and whatever plugins add. All tools, as on a Boox Go 7
  16. 16 Xteink X4 Firmware of its own runs on the Xteink X4 and X4 Pro; it comes to this site with its first release. Reading on the smallest device, in the emulator, as on an Xteink X4

The complete list

Each part of PaperPaw is a plugin of its own, a volume in the series, built with the same SDK as yours. Any of them can be switched off or replaced.

Dictionary01 Hyphenation02 Reader03 Reading aids04 Reading statistics05 Translation06 Vocabulary07 Wikipedia08 EPUB09 Plain text10 XTC11 Browser12 Calibre13 File browser14 File manager15 News16 OPDS catalogs17 Transfer18 Wallabag19 KOReader20 Progress sync21 Readwise22 Buttons and gestures23 Home screen24 Menu25 Menu editor26 Weather27 Widgets28 Default fonts29 Fonts30 About31 Battery use32 Diagnostics33 Keyboard34 Plugin manager35 Reading profiles36 Rules37 Screen lock38 Settings39 Setup40 Sleep screen41 Update42 Wi-Fi43
  • Reading
  • Formats
  • Library
  • Sync
  • Home and menus
  • Look
  • System

Change anything, fork nothing

Firmware for small readers is usually changed by forking it and keeping the fork in step. PaperPaw is changed from outside: what you see is plugins, built with the same SDK as yours, on a small kernel.

  1. On the device

    The home screen, every menu, gesture, tap zone, widget and rule are arranged on the reader itself, by touch or with buttons.

    Settings
  Customise menus
  Buttons and gestures
  Rules
Home screen: hold to arrange

  2. A folder of text files

    Translations, key maps, new defaults, fonts and styles. Copy the folder to plugins on the reader and it is there, on every device; on the Xteink readers, the plugin store on the reader installs it.

    plugins/large-print/
  plugin.ini
  i18n/*.ini
  keymap.ini
  settings.ini
  fonts/*.ttf

  3. A plugin with code

    A Rust crate against paperpaw-sdk adds screens, actions, formats, filters or services, or replaces the home screen, the library or the reading view outright.

    // in your plugin's register():
r.add_screen(home())?;
r.bind_slot(
    slots::HOME,
    HOME,
    Priority::PREFERRED,
)?;

Browse the plugins How to write a plugin The SDK on crates.io

Get it

PaperPaw runs as an app on Android e-readers today. It asks for no account and sends nothing anywhere unless you set up a sync yourself.

  1. Download the APK on the reader itself, or on a computer and copy it over.

  2. Open it to install. Android may first ask to allow installs from this source.

  3. On the home screen, allow “All files access” so PaperPaw can read your books. If Android greys the switch out, open Settings, Apps, PaperPaw and choose “Allow restricted settings” in the menu at the top.

Download for Android, 0.4.0

For updates as they are released, Obtainium can follow the releases page. F-Droid is to follow.

The Xteink X4 and X4 Pro get firmware of their own. It runs on both readers now and comes to this site with its first release, to be flashed from the browser. Flash the X4

Made in the open

PaperPaw is one person's project, written with the help of an AI model and tried on real readers. All of it is public: the code, the plan and how it is made.

First released on 15 October 2026. This edition: 0.4.0.

How PaperPaw is made

Particulars

Licence
Apache-2.0, the source on GitHub
Devices
Android e-readers (tested on a Boox Go 7); the Xteink X4 and X4 Pro once their firmware is released
Smallest target
Xteink X4: ESP32-C3, 400 KB of RAM, a heap of 256 KB
Formats
EPUB, FB2, Markdown, TXT, comics, PDF
Languages
English and German, more by plugins
Accounts, ads, tracking
None, here or in the app
Made by
One person, with the help of an AI