I have been doing some iPhone development lately.  So as part of this I started to port my windows chess game (SmartChess) to the iPhone.  So far, I have ported the logic for a 2 player game.  This includes the basics about chess like what moves are allowed, handling situations like check, pawn in the end, and en-passant. 
I still haven't ported the computer player logic yet, but it was fairly easy to port the rest of the c++ code so I don't expect any issues with that.  I am more concerned about getting the computer player to perform adequately on the iPhone.  I will continue working on this when I have a chance and should eventually have the computer player hooked in. 

Until I have completely ported the SmartChess code, I wanted to release what I have so I have called it Simple Chess.  The main purpose of this application is to be able to always have a chess board when and where I want it.  This way I can stop carrying the travel chess set around with me on vacation.