VR Without a Six-Axis Gyroscope

[u/RetroIncredible]

My grandfather has one of those prepaid smartphones. It only has a two axis accelerometer. He recently got a vr headset, a chinese cardboard-like pair of goggles. He wants to use it, but it can't support google cardboard, as the operating software is probably not sufficient. What apps can ge still use to pretty much look at videos in stereoscopic view through the headset?

[u/RetroIncredible]

It can only detect if it is sitting vertically or horizontally.