I bought this app for my three year old who LOVES Umizoomi. It is a GREAT app! Very easy for my daughter to navigate. There were some complaints prior to my buying it that the volume was was an issue. They seemed to have corrected the problem, however the volume is still a little lower on the songs than on the actual game. So when your child starts the app, it may seem a little low. However, once the actual game itself begins, the volume picks up. So when your child earns a trophy and everyone does the "Umi Shake," fear not, you're not getting old or going deaf, the volume does drop a few decibels. It's really the only criticism I have of this app. Oh, and parents should sit with their child when they reach a new level. While my daughter knows how to count, she found it a little confusing when actual math equations (simple ones, of course) were introduced. Once I explained them and we did a few together, she zipped through all of them on her own.