There is the list of supported gamepad on Android
* Amazon Fire Game controller and remote.
* Android TV controller and remote.
* GameStick on itself and on Linux.
* Google Nexus Player controller and remote.
* Green Throttle Atlas.
* NVIDIA Shield.
* OUYA Everywhere
* PlayStation 3.
* PlayStation 4.
* Samsung GP20.
* Xbox 360
* A variety of Xbox 360 clones are supported.
* Some generic Android controllers are supported.
* Some generic Blackberry controllers are supported.
* Keyboard and Mouse support.
I have planned to work on an update for Android with a configurable input system. I can't work on it right now because I'm on another game project (see GunSpinning VR). But this feature will come after summer.