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 5S iPhone 5S was discontinued on March 21, 2016, and succeeded by the iPhone SE, which continues the same form factor but features vastly upgraded internals similar to the flagship iPhone 6S. This was a break with Apple's product positioning trend (in North America and Western Europe), starting with iPhone 4S released in October 2011, which gave each newly released model one year as the flagship phone, then moving it to midrange for its second year of production, with the third and final year as the entry-level offering before discontinuation. While the iPhone 5S was expected to continue on sale until