Iskra for Android

A native Matrix messenger for Android — the same Iskra as on iPhone, iPad and Mac (iskra-app/iskra): the same features, the same words in seven languages, the same faces, the same bridge over nostr and the same privacy decisions.

Kotlin and Jetpack Compose on top; all of Matrix and all of its cryptography is matrix-rust-sdk through its official Kotlin bindings. Nothing cryptographic is written here.

Status: before the first release. Sign-in, chats, messages, media, encryption recovery and push notifications are in; see ROADMAP.md for what is done and what is left.

Installing

Iskra is published only as APKs on this repository's GitHub Releases. Pick one file:

• gms if your phone has Google services — notifications arrive through Firebase Cloud Messaging;
• foss if it does not — notifications arrive through UnifiedPush, with a distributor app such as ntfy; this build contains no Google libraries at all;
• arm64-v8a for almost every phone, x86_64 for emulators and ChromeOS.

Android asks once to allow installing apps from your browser. After that, Iskra checks for new versions itself (once a day, only a request for release.json to GitHub — it can be turned off in Settings → About) and installs them after verifying the download and its signature. If you prefer to manage updates yourself, Obtainium can follow this repository's releases.

Every release lists the SHA-256 fingerprint of the signing certificate. To check a downloaded file: apksigner verify --print-certs iskra-….apk. A file signed with any other key is not Iskra.

Building

JDK 21 and the Android SDK (platform 37). From a single clone, with no access to any other repository and no Firebase configuration:

./gradlew assembleFossRelease   # unsigned
./gradlew check                 # tests and lint

Two flavours: gms delivers notifications through Firebase Cloud Messaging; foss uses UnifiedPush and contains no Google libraries at all. gms gets push only when app/src/gms/google-services.json is present. How releases are cut: docs/RELEASING.md.

Licence

GPL-3.0 with an additional permission for app stores — LICENSE, LICENSE-EXCEPTION.md. The same licence as the Apple version. Generated avatars are a port of blobatar (MIT, Licenses/blobatar.txt); the bridge protocol in third_party/ is MIT.