The iBooks Author app for the Mac offers several features in creating books that can support the principles of Universal Design for Learning:
> "Text, audio, video and image together, providing multiple options for representation and engagement;
> Enlarge pictures and text so we can get up close;
> Re-play videos so we can repeat and revisit ideas;
> Listen to the text read aloud by Apple's built-in screen reader, Voice Over."
Go to the Apple help page "How to make your ibooks accessible" (support.apple.com/kb/HT5073?viewlocale=en_US&locale=en_US) to learn how to create a book that is accessible!