Kindle App . Information on the Kindle App can also be found on Amazon.
Somebody told me today that they looked for the book in the iTunes Store but could not find it. I explained that, after looking at various options, it was decided to keep the book exclusive to Kindle, as the Kinde App is free and widely available for most smartphones, tablets, laptops etc. For more see 'How to get the Book'. The Amazon store links have just been updated.
Thinking about getting the book? Why not check out some reviews ?