I've been having fun with the English/Bulgarian version of the BidBox Vocabulary Trainer, but I decided to get a non-educational game for those days when I just want to relax on the train. EA is holding a sale on its iPad game apps so I purchased Risk for $3.99 yesterday. I played through the tutorial version and the play was good. I liked the feature that allows you (and more importantly the AI) to continuously attack, thus saving a lot of dice rolls. I think the graphics are good and I didn't notice any sound, although one review on the games web page says it has sound.
For $3.99, I think the game is worth it. I can't spend two hours every day on the train trying to learn Bulgarian. I should, but my brain hurts too much.
NOTE: I have no business association with this game. If you purchase it, I do not get a dime.