The iPad versions feature some cool capabilities, like being able to click on a chapter in the Table Of Contents and be instantaneously taken there, or being able to search for a word and have a list of all the pages in the book including that term appear for you to check out, etc.
The Digital Real Book itself, including about 650 songs from all our fake books, is now downloadable to your iPad as well. Keep an eye out for more digital releases later in the year. Enjoy! - Chuck Sher