Zynga has gained a reputation as the evil empire lately, and to a certain extent that's true -- a lot of the company's Facebook "games" aren't much more than pyramid scams. But Texas Hold'Em poker is a game that will always have players, and for all of Zynga's drama, their Poker app has been pretty fascinating to me lately. I've been playing on Facebook mostly, but for those times when I'm away from home, the iOS app has served pretty well.
It's unfortunately very barebones -- the official Apple Texas Hold'em app is much better in terms of presentation, despite not being updated in quite a few years. But Zynga Poker's big selling point is not only that it shares a bankroll with your Facebook account, but that it's basically instant access, even on a 3G connection, to other online poker players, whenever you want it.
The money doesn't really mean anything (and you should be careful -- that means a lot of players just go all-in whenever they can, not worrying about their virtual financial standing), but for a quick and easy multiplayer game of poker, I've had a lot of fun with Zynga Poker lately. You'll need a Facebook account to play the free app, but once you get it up and running, if you're a poker fan, there's a lot of fun to be had.