We posted about another poker app back at WWDC, and the developer of Pokerbot got in touch with us to show off his app as well. Pokerbot is a little bit different than your standard hold'em poker game. It's a straight up one-on-one battle, so the game is really built for learning how to play poker well; it doesn't drag out games or rely on graphical flair. The game started out as a poker training program, and the developer of the game's AI is a real poker player who has played more than a few good hands.
That said, this probably isn't the app you want to get if you just want to enjoy playing at a full table; Pokerbot is meant for poker buffs or people who want to try to get to that level. There are little game touches that might turn hardcore players off (you can cheat with a feature called "Onetime" if you want, and there's a full achievements system thanks to OpenFeint). Most of the non-traditional touches are included in order to enhance the feel of the game, though; they aren't meant to make the poker action more casual.
Pokerbot is US $1.99. If you've never played poker before, it's probably a little bit much for you, and you're better off going with something like Apple's official game. However, if you know your antes, straights, and flushes, and you want a game that will present a nice challenge while teaching you to play better, Pokerbot will help.