It depends on the age of the kid... for a 2yo, moving pictures and talking characters in a book app offer similar benefits to pop-up books and those book-on-tap

It depends on the age of the kid... for a 2yo, moving pictures and talking characters in a book app offer similar benefits to pop-up books and those book-on-tape/CD/vinyl and deadtree book combos -- they help the child learn that the words have meaning, and demonstrate that meaning in a very accessible way, while keeping things interesting. For an elementary schooler, a book should be a book. Any interactivity beyond the "choose your own adventure" style will cause me not to purchase. There's something to be said for letting reading happen, instead of distracting with things that could have been left to the imagination. Over the elementary school age, I imagine that any child would find an "interactive book" at least as annoying and distracting as I do as an adult.