A free app for Android, by Flying With Gauss.

Xash3D FWGS – developed by Flying With Gauss – has been designed to serve as a branch off Xash3D Engine. It is supposed to be compatible with GoldSrc engine.

This fork permits you to play the game Half Life from out of its original box. But it also allows you to play other Half-Life based modifications.

This app requires Steam, a purchased game from the platform, and an installed Xash3D Android.

Settings are customizable. In Basic or Normal mode, you can manage the volume button mode as well as the system location of resources. In advanced you have the option to customize command line arguments (not advisable if you are not a programmer, or an expert in the subject), pixel format, and the ability to enable immersive mode.