IPhone OS 2 market." iPhone OS 2 cost $9.95 for iPod Touch users; it was free for iPhone users. IPhone OS 2 iPhone OS 2 is the second major release of the iOS mobile operating system developed by Apple Inc., being the successor to iPhone OS 1. It was the first release of iOS to support third-party applications via the App Store. iPhone OS 2.2.1 was the final version of iPhone OS 2. It was succeeded by iPhone OS 3 on June 17, 2009. iPhone OS 2.0 became available on July 11, 2008 with the release of the iPhone 3G. Devices running 1.x
IPhone 3GS more favorable reviews mainly because it comes pre-installed with iOS 4. Jason Snell of Macworld praised the iPhone 3GS, saying that "the device's internal changes shines in the iOS 4 update, making the iPhone 3GS a worthwhile upgrade compared to its predecessor although a little too late compared to the iPhone 4." TIPB stated that "aside from hardware specific features like FaceTime, Retina Display, and gyroscope support, the bottom line is iPhone 3GS users are getting the same software that makes the iPhone 4 great." Shortly after the release of the iPhone 3GS, some users reported overheating of the device