The iPhone 4 is a slate smartphone designed and developed by Apple. It is the fourth generation of iPhone, and successor to the iPhone 3GS. It is particularly marketed for video calling, consumption of media such as books and periodicals, movies, music, and games, and for general web and e-mail access. It was announced on June 7, 2010 at the WWDC 2010 at the Moscone Center, San Francisco, and was released on June 24, 2010 in the United States, the United Kingdom, France, Germany and Japan.
Prior to the official unveiling of the iPhone 4 on June 7, 2010, two prototypes were brought to mainstream media, breaching Apple's normally secretive development process. Many of the speculations regarding technical specifications proved accurate.
The iPhone 4 features an additional front-facing VGA camera, and an improved (backslide-illuminated, big physical pixel size) 5 megapixel rear-facing camera integrated with an LED flash. The rear-facing camera is capable of recording HD video in 720p at 30 frames per second. Both cameras make use of the tap to focus feature, part of iOS 4, for photo and video recording. The rear-facing camera has a 5× digital zoom.