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 system. The iPhone was initially released with two options for internal storage size: 4 or 8GB. On September 5, 2007, Apple discontinued the 4GB models. On February 5, 2008, Apple added a 16GB model. The iPhone 3G was available in 8 and 16GB. The iPhone 3GS came in 16 and 32GB variants and remained available in 8GB until September 2012, more than three years after its launch. The iPhone 4 was available in 16 and 32GB variants, as well as an 8GB variant to be sold alongside the iPhone 4S at a reduced price point. The iPhone 4S was available