Hello,
So as the title states, is it possible to integrate GearVR with a cheap 2-5$ controller(or any other cheap input device) that I can buy on eBay instead with the one from Oculus, the touch controller?
If yes, is there a documentation or anything about how to implement it?
Yes it’s no different than android. Bluetooth controllers that work with android or usb controllers with an otg cable will work. You can use my free controller tester application to find out the unity axis and button numbers on android since the Unity documentation is out of date. When you publish to the Oculus store for Gear VR you’ll have to select controller required if that’s your goal.
I will say the super cheap controllers under $15 are usually junk (high latency) but there are plenty of options at different price ranges.