That "odd one out" game is broken - it just generated 21, 14, 35, 49 and told me the right answer was "14" because it's the only number not divisible by 7. Also the prime number game generated a set of all composite numbers.
Thanks for the feedback. I will work this weekend to fix those bugs
+ Put all apps and books under one umbrella brand. Your book doesn't have a unique name associated with it. Little Math Genius or Little Math Whiz, for example.
+ Setup an umbrella website (littlemathwhiz dot com) and blog
+ Start aggregating a user mailing list where you can provide gentle updates (beta test new features on quizmathgenius, new book announcement etc)