IPhone 4S announced iPhone 5s and iPhone 5c. This was unusual for Apple as an upper case 'S' had been used since the introduction of the iPhone 3GS in 2009. On September 9, 2014, the iPhone 4S was officially discontinued following the reveal of the iPhone 6 and the iPhone 6 Plus. However, 4S production did continue for developing markets until February 17, 2016. On June 13, 2016, following the release of iOS 10, Apple dropped support on the iPhone 4S, making iOS 9.3.5 the last version available for the device. The runs iOS, Apple's mobile operating system. The user interface of
IPhone it later in June, July, and August, starting with the US, Canada and major European countries on June 19. Many would-be users objected to the iPhone's cost, and 40% of users had household incomes over US$100,000. The back of the original first generation iPhone was made of aluminum with a black plastic accent. The iPhone 3G and 3GS feature a full plastic back to increase the strength of the GSM signal. The iPhone 3G was available in an 8 GB black model, or a black or white option for the 16 GB model. The iPhone 3GS was available in both