The new software has been designed to make the iPhone appear bigger, with features crafted to take advantage of the entire screen.
Text is said to appear sharper, while a "control centre" on the phone allows users to adjust settings with just one swipe from the bottom of the screen.
This gives instant access to functions such as Airplane Mode, Wi-Fi, Bluetooth or Do Not Disturb, and enables users to quickly pause or play a song, jump to the next track and stream music.
Meanwhile a "notification centre" is available from the "lock" screen so users can view updates with a "simple swipe".
More top news
The great-grandmother-of-seven has explained why she won't retire from her fast food job after four decades - despite the 5am shift starts.
Sunshine gives way to cloud and showers
The Metropolitan Police Federation, which set up the official JustGiving site, said it felt a "suitable amount" had been collected.