Chapter 12: Running on Multiple iPlatforms and iDevices
The iOS SDK was announced to the public in February 2008. At that time there were only two devices using it: iPhone and iPod touch. Apple has since been innovating vigorously and in 2010, it introduced another bigger brother to the family, the iPad. In 2010, another new device running iOS was introduced: the Apple TV. Who knows what the future might hold—Apple might even announce an SDK for Apple TV development and may even enable running games from Apple TV controlled by your iPhone on iPod touch.
Every year, a new version of the SDK comes out along with at least two or three new device updates, and these new devices often come with additional sensors. The GPS sensor debuted with iPhone 3G, the magnetometer—a sensor used to show the direction of magnetic north (more commonly known as a compass)—debuted in iPhone 3GS, and the gyroscope (for lifelike game play) in iPhone 4. The iPad was introduced later with a whole new UI, a far bigger screen than the iPhone, but without a camera. iPad added a couple of cameras (including a front-facing camera) in the second iteration, iPad 2.
Similarly every version of the SDK comes with powerful new features: In App Purchases, Push Notification Service, Core Data, and MapKit support in iOS 3; multitasking, blocks, and Grand Central Dispatch in iOS 4; iCloud, Twitter integration, and Storyboards in iOS 5, to name a few. When you use one of these features, you might be interested in providing ...