Works great with iPhone 5 and Mountain Lion. Easy setup. I really like how the default theme matches Macbook keyboards. I was hesitant to spend the money given the reviews, but it's really a well designed app with a company behind it that seems to have a nice support team and a decent online presence.

Nice & simple, but keeps him captivated (23mo), but the lack of multi touch makes it very difficult for him to hold the phone and move items at the same time. (If one finger is touching the screen, another finger cannot provide input and move the shapes). Kinda old-style, but it is Houghton Mifflin after all ?. Maybe he'll be able to do it more easily in a few months.