I bought the Real Football 11 game some weeks ago, only $0.99. It's for iPhone/iPod touch.
Both my sons (5 and 8 years) play the game. The graphics is impressive with the grass looking almost like it does on the TV. The sound is quite realistic too. You choose your favorite teams and they feature the usual famous players. You have a local view and an overall dot view.
My kids love this game. I think that by playing it they realize there's more to the game than running and kicking the ball. The games are played with huge audiences at the top arenas and the player can easily get the feeling it's for real. A major advantage of playing the game is the increased interest in real-world football. This is not simply what I hope, but a fact.
I think the same goes for many a game, particularly sports games, that you get to try it on the iPod touch and that makes you want to try it for real. For educational games, the game becomes an additional study aid, which complements the books. More often than not, the game is probably a more entertaining tool than books are, and let's not forget that the nice devices the games are played on, make the studies more attractive.