LightQR

A QR scanner for the Light Phone III, and a companion web page that turns text into a QR code.

Part of the gi-os Light App collection.

Piece	What it is	Where
LightQR	Android tool. Scan a code, read the text, open the link, keep a history.	app/
QR Generator	Static web page. Type anything, download the code.	docs/, served by GitHub Pages

What the scanner does

• Reads QR codes with the back camera. CameraX supplies the frames and ZXing decodes them off the luminance plane. ZXing is pure Java, so it runs on LightOS, which has no Google Play Services.
• Takes a typed or pasted address instead, when a camera is the wrong tool.
• Shows the decoded text on a result screen. An Open link button appears for a URL.
• Keeps a local history of every scan and entry. There is no cloud and no account.
• Uses black on white, Akkurat type, and the LightOS top and bottom bars.

The generator

gi-os.github.io/LightQR encodes text in the browser. Nothing leaves the page. Use it to hand a long address to the phone without typing it.

Install

Obtainium, with automatic updates

1. Install Obtainium.
2. Add https://github.com/gi-os/LightQR as an app.

Every push to main publishes a new versioned release, so Obtainium sees each update.

Manual sideload

Download the APK from Releases and run:

adb install -r LightQR-vX.Y.Z.apk

On LightOS, set tool permissions to Any tools to launch it from the toolbox.

Releases and signing

.github/workflows/release.yml builds a signed APK on each push to main.

• versionCode is the CI run number. versionName is 1.0.<run>. The workflow tags the commit vX.Y.Z.
• The build signs with a fixed key, app/lightqr.keystore, so Obtainium can upgrade in place.
• The workflow attaches the APK to the release and marks it latest.

The keystore sits in the repo with default passwords, because this is a personal tool and a stable signature matters more here than a secret. To sign with your own key, set the repo secrets and pass them to the workflow as KEYSTORE_FILE, KEYSTORE_PASS, KEY_ALIAS and KEY_PASS. The Gradle config already reads those.

Build

gradle :app:assembleRelease

You need JDK 17 and the Android SDK, with compileSdk 34. The APK lands in app/build/outputs/apk/release/.

A note on the SDK

LightQR is a plain Android app. It does not use light-sdk. The trade is deliberate. CameraX and the standard soft keyboard work without an API allowlist, but the tool cannot enter the official Tool Library until someone ports it into the SDK tool module.

Screenshots

Scanner

Result, with OPEN and COPY

Taken on a Light Phone III.

Origin and credits

• gi-os/LightPass is where this started. The QR key scanner inside LightPass became a tool of its own, and LightQR keeps its CameraX setup and its Akkurat type handling.
• ZXing by the ZXing authors does the decoding. Nothing else in this space works as well without Play Services. Thank you.
• The Light Phone for LightOS and for opening the platform to community tools.
• Obtainium by ImranR98 handles updates, so this repo does not need a store.
• CameraX and Jetpack Compose do the rest.

Two later tools took from LightQR. LightRSS copied the docs/ generator page to make its feed QR codes. LightFog copied the release workflow, because plain Gradle in GitHub Actions beats an EAS build for a single-developer project.

The gi-os Light App collection

Twelve tools for the Light Phone III, all open source, all built in one run.

Tool	What it does	Built on
LightPass	Photograph a movie ticket, keep the stub	Plain Android
LightQR (this repo)	QR scanner, plus a browser generator	Plain Android
LightRSS	RSS and Atom reader with images and QR subscribe	light-sdk, fork of zachattack323/LightRSS
LightNYCSubway	Live MTA subway arrivals	light-sdk fork
chat	iMessage over a self-hosted BlueBubbles server	Fork of craigeley/chat
LightFog	Fog of World companion, GPS recorder and fog map	Fork of garado/light-topographic
LightNonogram	Picross, plus a generator that only ships solvable puzzles	Kotlin generator, light-sdk tool
LightSolitaire	Klondike, draw one, unlimited redeals	light-sdk
LightFastread	RSVP speed reader for EPUB and MOBI	Fork of fluffyspace/FastRead
LightTip	Tip calculator, plus a receipt splitter that reads the line items	Plain Android
LightNoise	Twelve synthesized sounds, a two-layer mixer and a sleep timer	Plain Android
LightPods	AirPods battery, in-ear and lid status	Plain Android, ports LibrePods

The Light Phone does not sponsor or endorse any of these. Licences vary per repo.

License

MIT. See LICENSE.