B2G OS is described as 'B2G is a community maintained open source operating system for smartphones, tablets, smart TVs and other connected devices. The project was started in 2011 and is based on the Linux kernel and Gecko rendering engine' and is an app in the OS & Utilities category. There are more than 10 alternatives to B2G OS for a variety of platforms, including Linux, Android, Self-Hosted solutions, iPhone and Android Tablet. The best alternative is Android, which is both free and Open Source. Other great apps like B2G OS are Plasma Mobile (Free, Open Source), iOS (Free), Sailfish OS (Free) and Tizen OS (Free, Open Source).
iOS is a mobile operating system developed by Apple Inc. and distributed exclusively for Apple hardware. It is the operating system that powers iPhone, iPad and iPod Touch. Each main version of iOS / iPhone OS has introduced a big, main feature of the new version.
Astian OS is an operating system that is based on the discontinued Firefox OS, development by Astian Foundation, thus allowing support for mobile devices, TV's, and other devices. Astian OS is completely free and open.