My 4 1/2 yo loves this app! She is motivated and feels accomplished when she solves a question and gets points to acquire more monster parts. Admittedly, her favorite thing to do is blow them up, but in the interim she has mastered simple addition and is now learning simple subtraction, simple division (halves, quarters, etc) and is curious about even and odd numbers. This app has supported her learning with me - mostly because the app is as tireless as she is and there are only so many times I can set up objects for her to calculate before I reach my limit. I like that I can customize her learning so that it's appropriate to her level - she's not yet ready for double digits. She was getting frustrated using big sister's profile so I made a new one for her where she has built her confidence and looks forward to her time on the iPad so she can play her monster math game. All in all, I have no complaints - rare indeed for an expensive app. It's stable and responsive on our iPad 2 and my iPhone 6P. The music/audio is pleasant and not annoying. Love love love!