A custom ROM is essentially a firmware based on the Android source code provided by Google. A lot of people prefer custom ROMs because of the functionality they offer, and the ability to customise many things on the phone. … Here’s a quick guide on how you can install a stable custom ROM on your device.

Should I use custom ROM?

Installing a custom ROM puts you in control of your own hardware. You can swap out one operating system for another, tweak more settings, and change the experience until you’re as happy with Android as you can get. Then your phone is truly yours to do with as you please.

How can I customize my android?

Download and build Android from the Android Open Source Project, then modify the source code to get your own custom version. Simple! Google provides some excellent documentation about building AOSP. You need to read it and then re-read it and then read it again.