Voicepad

Voicepad is a reMarkable Paper Pro takeover app with a native Android companion. Speech and keyboard input share one persisted editable document and cursor. Remote finger ink and tablet pen annotations are composited over that document.

Install and pair the Android companion

1. Start Voicepad on the tablet.
2. Put the Android phone and tablet on the same Wi-Fi.
3. Scan the QR shown by Voicepad.
4. Tap Download the Android app and open voicepad.apk.
5. If prompted, allow the browser to install unknown apps.
6. Return to the scanned page and tap Pair and open the installed app.
7. Grant Voicepad microphone permission and tap Start microphone.

The app can also find Voicepad by UDP broadcast or accept the tablet address manually. The companion is signed with the local Voicepad debug key at ~/.android/voicepad-debug.keystore; keep that key to install future builds as updates over the existing app.

The companion supports:

• continuous native Android speech recognition inserted at the shared cursor;
• live Bluetooth keyboard forwarding while the app is open, including arrow cursor movement, Enter, Tab, Backspace, Delete, Home, and End;
• finger drawing and erasing from the phone;
• Android-selected Bluetooth microphones/headsets.

This is a LAN-only development build. Port 7777 is unauthenticated, so use it only on a trusted network.

Document and ink model

Voicepad stores Unicode code points in an editable linear document with a cursor and deterministic fixed-grid layout. The document and cursor persist in voicepad-document.txt and voicepad-cursor.txt. They are also available over GET /document and GET /state, allowing later automation to edit structured text directly rather than recovering it from screenshots.

Rendering uses separate static-paper, generated-text, and manuscript-ink layers. Pen input is retained as document-positioned, tool-tagged vector segments. The eraser currently renders as a persistent white mask, but remains identified as an eraser gesture so it can later become a strike-through or candidate-deletion annotation without changing the text representation.

Fast interaction and cleanup are split into two phases. Pixel diffs and the visible cursor use quill_swap_mono_fast() immediately. The cursor is hidden and debounced during bursts, so intermediate arrow/key positions never reach the panel. Retired changes are unioned into one exact focus rectangle; after 400 ms idle it receives at most one quill_swap_mono_quality() call. This path always uses full=0, rejects regions taller than 192 pixels, and can therefore never promote background cleanup into a whole-screen refresh.

Build

Prerequisites are a JDK and Android SDK. The build script uses aapt2, d8, zipalign, and apksigner directly, so Gradle is not required.

cd voicepad/android
./build.sh

The signed APK is written to android/build/voicepad.apk. To cross-build and stage the complete tablet bundle:

cd quill
./build.sh
cd ../voicepad
./build.sh
./make-bundle.sh

The bundle appears in voicepad/dist/voicepad/, including voicepad.apk, which the tablet serves from GET /voicepad.apk.