SOHL12Launcher is a separate app which uses Xash3D FWGS engine.
To play it, make sure you followed these steps:
1) Installed Xash3D FWGS and this app from play market.
2) Copied "valve" folder from your Steam account to your Android device. (e.g. to "xash" folder on your device storage. If you choosed another folder, make sure you are choosed this in Xash3D FWGS app)
3) Copied any mod folder with game data downloaded from list at link below on your device.
4) Added -game [modfolder] key in cmd args.