"The iPhone 4 is a touchscreen 3G smartphone developed by Apple Inc. It is the fourth generation iPhone, and successor to the iPhone 3GS. It is particularly marketed for video calling (marketed by Apple as FaceTime), consumption of media such as books and periodicals, movies, music, and games, and for general web and email access. It was announced on June 7, 2010, at the Apple Worldwide Developers Conference (WWDC) 2010, held at the Moscone Center, San Francisco, and was released on June 24, 2010, in the United States, the United Kingdom, France, Germany and Japan.
The iPhone 4 runs Apple's iOS operating system, the same operating system as used on prior iPhones, the iPad, and the iPod Touch. It is mainly controlled by a user's fingertips on the multi-touch display, which is sensitive to fingertip contact. It originally shipped with iOS 4. The latest version available is iOS 7 (September 18, 2013)."