The Pose Drawing Sparkbook is a workbook of sorts I designed to help artists put more life into their drawings, and it’s finally made it to the iBooks store. Well, the Basic version is there. I’m still waiting for the Expanded version to be approved by Apple, hopefully very soon. (The Expanded version includes 200 bonus sketchbook ideas in the back of the book that are not included in the physical book or the basic ebook).
I currently sell the ebook in my own store in three formats: PDF, Kindle, and Nook/ePub (the PDF version is by far the most popular). Unfortunately Apple’s policies prohibit me from selling the iBooks version anywhere except in their store, so if you want that format you have to get it through them.