I have seen a few posts that reference Sudoku apps, but have not seen a dedicated thread. I was wondering anyone who HAS PLAYED one of the several Sudoku apps opinion on it. Please give a short description on why you would rate it x/10 (0-10 scale). Thanks. I don't really care about price, but a few options I would weigh into the decision are the ability to listen to music while playing (though iPhone iPod) and the ability to enter custom games (from your newspaper, etc.).