History of Apple Inc.
The first version of the iPhone became publicly available on June 29, 2007 in selected countries/markets. It was another 12 months before the iPhone 3G became available on July 11, 2008. Apple announced the iPhone 3GS on June 8, 2009, along with plans to release it later in June, July, and August, starting with the U.S., Canada and major European countries on June 19. This 12-month iteration cycle has continued with the iPhone 4 model arriving in similar fashion in 2010, a Verizon model was released in February 2011, and a Sprint model in October 2011, shortly after Jobs' death.
IPhone 5S
The 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 September 2016, replacing it and its A7 processor early meant that Apple "just reduced its long-term chip support window by a year" for iOS. In addition, a new iPhone launch was meant to stimulate demand, as sales of iPhone 6S and 6S Plus had not met expectations since their September 2015 release and the iPhone family was expected to suffer its first ever negative growth quarter in 2016.