Another fantastic book, this time authored by Lukas Mathis. If you have any interest in iOS app design (and if you have an interest in iOS development, you should!) then I can't recommend this book enough.
By the way, just in case it isn't clear none of the links in iOS dev weekly are sponsored. I just wanted to link to both of these books! If we ever do do sponsored links then they will be clearly marked as such, however there are no plans for that right now.