RxJava – Reactive Extensions for the JVM – a library for composing asynchronous and event-based programs using observable sequences for the Java VM.

BookLore: A self-hosted, multi-user digital library with smart shelves, auto metadata, Kobo & KOReader sync, BookDrop imports, OPDS support, and a built-in reader for EPUB, PDF, and comics.

An android library for section headers that stick to the top

Allows you to emulate an Android native library, and an experimental iOS emulation

A Real-Time Audio Processing Framework in Java

Small library that wraps Google Play Service API in brilliant RxJava Observables reducing boilerplate to minimum.

Etherpad Open-Source Repository

Visualize haarcascade files for Viola Jones algorithm

Android example for smooth true north compass values

A suite of adapters designed to provide alternatives to Android's provided adapters