CyanogenMod is a replacement firmware of over 60 smart phones and tablet computers, based on the Android mobile operating system. It offers features and options not found in the official firmware distributed by vendors of these devices.
This project is discontinued, the community created a successor project called LineageOS.
F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.