Cool, but I still prefer "Books Not Apps" for our children.
Also, regarding books, there is, historically, a lot of content.
For example: I learned how to use the graphics system in Realtalk with a physical booklet that I could have taken home and studied. The booklet had the code printed out on it, as well as hand written annotations from previous readers. The "magical" part was putting the booklet in a space running Realtalk and seeing live examples of the code projected onto each page as I flipped through the book.