I've got to take issue with other reviewers here. I did not find this inspirational or useful and, in many ways, you can find out more by just browsing the web. The early sections actually are useful: a good introduction to the strengths and weaknesses of the iphone and in particular the iphone camera. The section 'craft your toolkit' is great at showing how you can do more than just point and shoot with the iPhone.
Sadly from there it goes downhill. Had the book stopped at that point it would have been rather brief but useful. Instead we then go though a catalogue of photography apps (browsing the App store is better for this) and then 'inspiration'. Or thumbnails of photos that are really not very inspiring. Finally we move on to presumed professionals' photos and profiles. That is not what this book, from it's title, should be about. It is billed as a guide to photography with the iPhone, not a critique of other photographers works.
I feel a bit mean giving it only two stars but, if you bought it by the title and description you would feel short changed. It's something of a shame admittedly because it is a well produced and well written book: it simply does not focus on it's raison d'etre.
Sorry.