1. PokerCruncher - it's basically PokerStove for the iPhone
2. PokerTracker - from a different person that does PT3, but it tracks sessions for you playing online or live, you just enter in the session details (no VPIP or anything like that)
I've found that most of the poker games for iphone kind of suck.
Hellmuth's game was laughable and didn't save between sessions
The apple version is... well everything is OK but the AI.
ThTouch was the original I used, and it still feels rough around the edges.
I won't even mention zynga poker.
But PokerCruncher is nice, I like having it on hand when I'm thinking about certain hands, etc. But I end up having Stove installed on most of my PC's.
I've just launched a new port of PokerStove for the iPhone called PokerSniper - it uses hand notation entry rather than drag and drop... check it out, it's pretty cool
In case anyone else is in need of a Pokerstove type application on their iPhone, I just d/l this app called "Poker Odds Calculator Pro" that I wanted to highly recommend. It was just added to the store 12/28/09 so people may or may not be aware. It has a very nice interface, and you can even save custom hand ranges. It is super easy to use. For $1.99, this thing is the nuts.
I'm just a bit addicted to Chinese Poker and Seventeen (Chinese w/ Badugi & 2-7 Lowball) from http://www.acesquared.com/. How such random games could have iPhone apps I'll never know, but I am very thankful that they exist.
I use Michael Golden's Poker Journal to record live cash and tournament play. It's pretty good but it's been 5 months since the last update and it needs some new features and bug fixes.