Unity Home: http://www.facebook.com/CounterStrikePort
Thanks to XDA developer TiP@H, a mobile version of the game (called Counter-Strike Portable – no technical or official relation to the original Valve title) has been ported to Android in a pre-release test form. Online multiplayer is fully present (though it appears limited to some weird Matrix map with Zombie mode?), and there’s a single-player version with ‘bot’ enemies and allies that you can download as well.
Download : CounterStrike for Android