This is an app for both iPhone and iPad. I put together a 12 page book fairly easily yesterday. Of course on the iPhone, you don’t want to do a text heavy book.
I found it did not like the vertical photos from my Photo Roll. I had to open them in Photogene, rotate them 360º then save. I am not certain if the problem was how they were saved in my photo roll (Pictures were from 2 years ago) or if the app favors landscape.
This would be fun to create a picture book that you could share with parents, grandparents, etc showing a special event in the class room. It creates an EPUB. Not sure how it would look on other readers, but it looks nice in iBooks.
You can see screenshots of the book taken from my iPhone on my Sara Talks Apps posterous site. (See links “Using the Apps” in the sidebar.)