Good iOS developers know that design is very important. That’s why many of them had to revamp their apps for iOS 7. Luckily, someone out there has written a book to help those folks design their apps.
Nathan Berry’s book goes over many parts of the process, which include taking an idea from rough sketches to final product. Also involves is Apple Design Award-winner Jeremy Olson. According to CultofMac, it’s pretty easy-to-follow, but can set you back quite a bit if you want the full package. The book costs $29, but there is additional content, such as video interviews, Photoshop tutorials and other resources that bring it up to about $200.
You can take a look at it here.