/e/ is described as 'fork of LineageOS that aims to be completely free of everything Google. Not only that, but there are a number of goals the developer has in mind for /e/ that more people feel are vital to a mobile operating system' and is a popular Android ROM in the OS & Utilities category. There are more than 50 alternatives to /e/ for a variety of platforms, including Android, Linux, Android Tablet, Linux Mobile and iPad. Most alternatives are Android ROMs and Mobile Os. The best alternative is LineageOS, which is both free and Open Source. Other great apps like /e/ are Android (Free, Open Source), Ubuntu Touch (Free, Open Source), GrapheneOS (Free, Open Source) and Replicant (Free, Open Source).
Flyme is a stock and aftermarket firmware developed by Meizu for smartphones based on the Android operating system. Some of its key features are completely redesigned apps, one-handed usability and performance optimizations.
Asus Zen UI (stylized as ASUS ZenUI) is a front-end touch interface developed by ASUS with partners, featuring a full touch user interface. ZenUI is used by Asus for Android phones and tablet computers, and is not available for licensing by external parties.