GzDoomVR is port of GzDoom into VR
GzDoomVR code under GPL licence can be found here: https://github.com/lvonasek/GZDoom-Android
The app contains Doom 1 shareware wad under this licence:
https://raw.githubusercontent.com/ChrisJan00/WarrensDream/master/doom-wad-shareware-license.txt