Books Continue to Evolve - Check Out E.O. Wilson's 'Life on Earth' iBook
Life on Earth is a digital biology textbook for high school students. It's currently "under development" (it isn't being written, it's being developed) by the E. O. Wilson Biodiversity Foundation. The free download offers a preview of the book and a sample chapter about ecology. New chapters will be "released" (not published) over the next 2 years to the Apple iBookstore.