I have the book in front of me. I paid $7.39 for it on Amazon, including shipping. This app is not the book. The menu is crude, the tutorial is far more brief than the book and none of the images are scaled for my ipad air2 resolution, resulting in very pixelated background and menus. The menu icons are ever present and theres some silly option for a zoom 1x or 2x which doesnt zoom at all - but zooms out to an even smaller resolution. The options dont save and the sound clips for many of the chords have pops and clicks. I would not recommend this app to anyone who is unfamiliar with the book. This was a simple thing, shame it got botched.
Alowishes509 about The Chord Wheel, v1.1