Appcelerator Titanium - Appcelerator Open Source
PortAudio - PortAudio is a cross platform, open-source, audio I/O library.
React Native - A framework for building native apps with React
JUCE - JUCE is a wide-ranging C++ class library for building rich cross-platform applications and plugins...
Onsen UI - HTML5 Hybrid Mobile App UI Framework - work with Angular, React, Vue, Meteor & pure JavaScript. Material & Flat design.
OpenAL Soft - OpenAL Soft is an LGPL-licensed, cross-platform, software implementation of the OpenAL 3D audio API.