This app hits such a sweet spot. I bought this for my homeschooled four year old on the strength of the base app. I could hear him play it every day (the intro theme is darn catchy). As I watched him play it, I saw him figure out several concepts that hed struggled with in the past -- two- and three-part patterns in particular. The way this app presents them with subtle music and visual clues is a brilliant example of how technology can actually augment the learning experience if its done right. And this app does it right, across the board. I wound up paying for the full app. Even though it was expensive, it was clearly worth it. The best part is that it doesnt feel like learning to him -- just a really fun game. And thats how learning should be.