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 predefined extensions. The iPhone does not support Flash, which was still popular when the iPhone was introduced. Consequently, the UK's Advertising Standards Authority adjudicated that an advertisement claiming the iPhone could access "all parts of the internet" should be withdrawn in its current form, on grounds of false advertising. In a rare public letter in April 2010, Apple CEO Steve Jobs outlined the reasoning behind the absence of Flash on the iPhone (and iPad). The iPhone supports SVG, CSS, HTML Canvas, and Bonjour. Google Chrome was introduced to the iOS on June 26, 2012, and Opera mini is also available.