Friendar

Friend radar for Android. Follow the arrow to the friend you're looking for.

Friendar points you at a friend's phone when you are both nearby, using ultra-wideband (UWB) with Bluetooth, Wi-Fi Aware and GPS as fallbacks. Open the app on two phones, tap Start, and follow the arrow. It works with no mobile signal or Wi-Fi network.

Install

Download and install friendar-<version>.apk from the latest release on Android 12 or newer.

Privacy

There is no pairing or encryption. Any phone nearby running Friendar with the app open can link to yours, and linked phones send each other their GPS position.

Build

./gradlew assembleDebug
./gradlew testDebugUnitTest

You need JDK 21 and the Android SDK with platform 36 and build tools 35.0.0. The APK is written to app/build/outputs/apk/debug/.

Docs

• Architecture explains how the link, UWB sessions and measurement fusion fit together.
• Decisions records why things are the way they are and what was ruled out.

License

MIT