I am on UE 4.16.1 (stock) and this is my initial setup (on tick EV_GearVRController is called):
Controller shows up in the game (since I run dev build from apk, I have to press any button on the controller for it to initialize), but it doesn't rotate with camera (doesn't stay on the right side) as I turn 360 deg. in the swivel chair. Also, pressing trigger button does nothing (action is mapped to Motion Controller R trigger in the project's Input settings).
I checked sample from github, but it's not even remotely related to Gear VR controller (I didn't see the component or any BP nodes related to it used).
I am not sure if Enable Arm Model node works at all - the tool tip on it is from CPU/GPU node and there no docs on what it does (I assume it should automatically place controller into its default position and have it swinging as user tilts/turns/rotates it, similarly as it's in the Dead and Buried for Gear VR).
Could you please explain how to get it going ?
P.S. On top of that controller doesn't duplicate touchpad functionality - nothing happens when I press touchpad on the controller (thus, it's doesn't duplicate touchpad on the HMD). Someone tested my app before I added BP nodes for the controller and the effect was the same - controller's touchpad didn't do what it suppose to do.