The dartboard format is different and the randomizing of the problems is good. When moving back and forth between operators it can be easy to forget what operator you are doing, which can cause some wrong answers. The concept is somewhat unique and promising, but I dislike some of the implementation choices. For example, the answer keypad just uses the standard iPhone keypad which contains more keys than necessary and takes up more room, while keeping the keys pretty small. Also, at some point you need to enter a player ID but there doesnt seem to be any way to change players; since I intend to have 3 kids sharing this I would like to be able to keep them separate. Another complaint is that the app only provides a high score table - there is no way to review the days progress. Also, the "products" page is just a big advertisement. Finally, when I pressed the in-app upgrade button to see the price of the multiplication module, I wasnt able to cancel the purchase even though I pressed the cancel button. I guess what it comes down to is this is more of a game than a study tool. I was really looking for an innovative and interesting study tool. This has promise, but it falls a little short.