During today’s media event, Apple also announced when iOS 9 will launch. The new iPhones will launch on September 18, but Apple always likes launch updates before a new iPhone. Thus, we’ll see iOS 9.0 come out on September 16.
This update will be available for the iPhone 6, 6 Plus, 5s, 5c, 5, 4S, iPad Air 2, Air, 2, 3, 4, iPad mini 3, 2, 1, and iPod touch 5, and 6. Unlike previous year, this year you only need 1.3 GB free on your device. Before, you needed 4.58 GB free in order to install it. You can learn more about iOS 9 here.