sorry for my bad english i'm italian. i just bought this amazing app on my nvidia shield tablet, there is a gamepad specifically made for this tablet, and simply do not work whit drastic, and when i configure the key mapping in the external controller section it works until the d-pad key, where it just stop working even if i am smashing the up thing.
Edit: sry my bad, the tablet had to do some big update, it run perfectly now. great work with this app by the way.