History of iPhone
On January 9, 2007, Steve Jobs announced iPhone at the Macworld convention, receiving substantial media attention. Jobs announced that the first iPhone would be released later that year. On June 29, 2007, the first iPhone was released.
IPhone 4
The iPhone 4 spent the longest time as Apple's flagship iPhone model at fifteen months. Although the succeeding 4S was announced in October 2011, the 4 continued to be sold as a midrange model until September 2012, and thereafter as the entry-level offering in Apple's lineup until September 2013 with the announcement of the iPhone 5S/iPhone 5C. The iPhone 4 had the longest lifespan of any iPhone ever produced, spanning close to four years and available in some developing countries until early 2015.