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 placement of the microphone and speaker on the base on the unit—the speaker is on the right. Volume controls are located on the left side of all iPhone models and as a slider in the iPod application. The 3.5mm TRRS connector for the headphones is located on the top left corner of the device for the first five generations (original through 4S), after which time it was moved to the bottom left corner. The headphone socket on the first-generation iPhone is recessed into the casing, making it incompatible with most headsets without the use of an adapter. Subsequent generations eliminated