My 4 years olds kindergartens follows the method of Montessori, so when I found this apps, I am quite excited. My wife also bought a set of physical Montessori tools but we seldom play with my kids. But with this apps on my iPad, it is much more convenient. Actually, after a fews days, he could play it by himself without guidance. The only thing I want to improve is about the user interface. Its great but my kids need to wait until the voice is finished before he could drag the letters. It made him a little bit confused because he couldnt wait and started to drag. BTW, I think I will buy more apps if they make it.