And while you’re at it, make sure to check out Beloko Games’ site. He posted all his ports for free after he got banned from Google Play (for using copyrighted images? I don’t know). Jedi Outcast & Jedi Academy in particular are still incredibly good games today, better than any native mobile game. And he made Quake 1-3 ports, as well as Return to Castle Wolfenstein.
And if your want some really serious action, check out DIII4A: that one’s a Doom 3 port (!!!) for Android. With a little tweaking, I was able to run it full speed on my old Note 2, and on my S7, it’s running smoothly with Ultra Detail. ??
As with Half-Life, you’ll need the original game files for all these ports. They all have great, completely configurable touch controls, so they’re all worth playing.