Code with testing in the browser
In particular look at
Overall this is (as of January 2016 at least) Javascript so you can look at the code of what you import. This is important as you can extend it if need be.
The cube rotates but... there is a MISTAKE in the code (again!) Fix it and enjoy the cube in... VR!
Try Mission 2 to naturally use your VR headset! Please only do that after have the demo working in your headset, not just as 3D but as VR proper.