What is most popular way other than unity?

Target Platforms Mobile
1

to develop android game, apps?

unity3d is number 1?

if not, what is?

if yes, what are others popular?

Thx.

2

http://mobilegameengines.com/android/game_engines
Here is a rather big list of game engines for Android, but it seems to miss some rather big engines like Unreal.

And here some more fact statistics about dev tools used, not just game engines.