Android - Android is an open source mobile operating system initially released by Google in 2008 and has since become of the most widely used operating systems on any platform.
LineageOS - Operating system for smartphones and tablet computers, based on the Android
CalyxOS - Privacy-focused operating system for smartphones based on Android and microG
Sailfish OS - At the heart of Jolla is Sailfish OS, the independent mobile operating system offering an alternative to the existing dominant systems. Sailfish OS is the perfect solution for country ecosystem and corporate mobile projects, or for consumer devices.
GrapheneOS - GrapheneOS is an open source privacy and security focused mobile OS with Android app compatibility.
PureOS - A user friendly, secure and freedom respecting OS for your daily usage