At present, the Movie and Book applications are available at the App Store; Games and Music are currently awaiting approval. Programs will work on both iPhone and iPod Touch and are available for $9.99 each. Users also need the latest Pro version of the Movie Collector or Book Collector. Currently the Windows version is available; the Mac edition is expected by August 2009.
For Book Collector, while the app is "viewer only," users will be able to search for books already in their collection avoiding duplicate book purchases, manage a book Wish List, and view facts about the book.
If you purchase a lot of books and can't always remember what is on your shelf, Book Collector and the mobile version could be a very useful tool for genealogy conferences and exhibit halls. Right now, I don't know of other apps that offer both a Windows and Mac database and an iPod Touch/iPhone application. If you know of a similar software situation, please leave a comment; I'd like to hear about it.