I used the gamepad plugin in construct2 and made an apk by xdk as you posted in this forum for crossover cordova (thank you very much for it!) The joystick is named: amazon fire game controller. I didn't use the remote control, but you can use the amazon game controller as remote control too. The game controller works very fine!!
I hope to publish my game "Hell Eagle 3.0" for amazon fire tv for free. I will post it, when I have finished it.
P.S.: I have to use the stick remote. The Gamepad on fiertv doesn't work with the Gamepad plugin