Termux - a terminal emulator application for Android OS extendible by variety of packages.

Barcode Scanner Libraries for Android

Open source Old School RuneScape client

Apache Heron (Incubating) is a realtime, distributed, fault-tolerant stream processing engine from Twitter

Blue Ocean is a reboot of the Jenkins CI/CD User Experience

GeoGebra apps (mirror)

An Android library that prevents your app from being pirated / cracked using Google Play Licensing (LVL), APK signature protection and more. API 14+ required.

Provide Fingerprint, Touch ID, and Face ID Scanner for React Native (Compatible with both Android and iOS)

The NASA WorldWind Java SDK (WWJ) is for building cross-platform 3D geospatial desktop applications in Java.

A simple Android class for encrypting & decrypting strings, aiming to avoid the classic mistakes that most such classes suffer from.

Example use cases from the O'Reilly Graph Databases book

iOS/Android thumbnail generator with support for both local and remote videos

A software acoustic modem for the Android Team Awareness Kit (ATAK) that allows multiple ATAK devices to share data using only voice comms (e.g., over a walkie talkie)

Simple app using JNI to read files inside the app's Assets folder