iOS 4, Apple's advanced mobile operating system, has introduced new and improved features to the iPhone/iPad SDK, including multitasking, the accelerometer, mapkit, push notifications, in-app purchasing and iAd. Originally developed for the iPhone, the system has since been shipped on the iPod Touch, iPad, and Apple TV. iOS 4 in Action, a completely updated edition of iPhone and iPad in Action, goes beyond the basics of iPhone OS development, to provide readers with everything they need to create fully-functional, store-ready apps. Completely illustrated and easy to pick up, this book contains an array of sample apps to help readers learn from the ground up, one step at a time. Readers will then be shown how to apply this new skill set toward more advanced projects.