I'm ashamed to say I've been bugging the Dragonbox people for quite a while to get this app ready for Kindle Fire. They got back to me this morning and said they had fixed the issues with it for Fire and it was okay to go ahead and buy it. If you purchased it before this update you should probably re-download it. I took it straight to my daughter and she picked apples in the Noom's apple field for almost 3 hours when her Kindle Fire HDX 7" battery went dead. We had no issues with it whatsoever. She said it was an awesome app and loves it even more than the first Nooms app. I've been watching her play and it's super cute! These people are real artists. It does simple addition and subtraction and also multi-digit addition and subtraction. It guides them on what to do each step of the way and if they mess up it will help them. They have to write in numbers with their finger sometimes and amazingly it accepts my daughter's sloppy handwriting. In the game you collect resources and trade them in for other things you need to unlock the rest of the game. They choose what to work on and there are a lot of things to do so they won't get bored with this. I can see this app taking a long time to complete.
I may update this review as we get further into it but you can't go wrong with Dragonbox. I just wish someone would have made an early reading app with as much attention and care as these people did with early math.