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 4 million iPhone 4s were sold in its first three days of availability. The iPhone 4 has also been released through Orange in Tunisia and was available in eight cities at the launch. On July 30, 2010, iPhone 4 was made available for sale in Australia, New Zealand and 15 other countries with free bumper cases. In South Korea, it was released by KT on September 10. In Israel, it was released, too, on September 24, through Cellcom, Pelephone and Orange. It was launched in Thailand on September 23 by AIS, DTAC and True Move, and in Malaysia on September 26