the author of this app says:
iBooks is an amazing way to download and read books, designed exclusively for iPad. iBooks includes the iBookstore, where you can download the latest best-selling books or your favorite classics day or night. Browse your library on a beautiful bookshelf, tap a book to open it, flip through pages with a swipe or a tap, and bookmark your favorite passages.
Compatible with iPhone, iPod touch, and iPad. Requires iPhone OS 3.2 or later. Application is free, content is not free.