The title on this one pretty much says it all - the iOS Design Cheat Sheet is a collection of useful information for iOS developers.
When you are designing a lot of applications for Apple’s touch devices like the iPhone or iPad you often have to follow some conventions regarding sizes or radii of Icons, Buttons or Tables. Because it is always a big time loss if you have to search on the Web for this information again and again, I’ve put the most important specifications into a nice iOS Design Cheat Sheet.
Useful.