Apple iPhone 4 / Specification

The iPhone 4, announced on June 7, 2010 and released on June 24, marked Apple's most dramatic redesign of the line to that point. It abandoned the curved plastic of earlier models for a flat sandwich of glass front and back held in a stainless steel frame that doubled as the phone's antenna, giving it a more industrial, jewel-like feel. At launch it was the thinnest smartphone Apple had made, just 9.3 mm thick.

Its headline feature was the "Retina display": a 3.5-inch 640x960 LCD at 326 ppi, a pixel density high enough that Apple claimed individual pixels were indistinguishable at normal viewing distance. The iPhone 4 was also the first iPhone with a front-facing camera, debuting FaceTime video calling alongside a 5 MP rear camera capable of 720p video. Inside, the new Apple A4 chip—Apple's first self-designed phone processor—was paired with a three-axis gyroscope, enabling far more precise motion sensing for games and apps.

The launch was overshadowed by "antennagate": because the external steel band served as the antenna, bridging a gap on the lower-left edge with a bare hand could noticeably drop signal strength. Apple acknowledged the issue and offered free bumper cases. Despite the controversy, the iPhone 4 sold strongly and remained a long-lived model, supported through iOS 7. From about $199.