I thought the solar system book was incredible and I am going to talk to my wife about using it as a home school resource. I would definitely love to see more materials show up that are like this. It would be great to have some options for turning things on and off, like page flipping, removing some of the higher level math as it might throw off younger students, and it would be great to have a lock-in mode.

The lock-in mode would be a parental control that keeps a child from going to other sites, so that I could set my kid loose on a book and know they aren't playing video games.

While I acknowledge that other platforms make e-books and interactive books, I love that you are making a centralized location on the web for the creation and curation of these resources.