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
A former member of the Bank of England's Monetary Policy Committee has told ITV News interest rates need to rise "sooner rather than later".
A Florida police officer has been suspended after footage showed him throwing peanuts at a homeless man 'like he was a circus animal'.
A German doctor has been charged with negligence after declaring an elderly woman dead, only for her to awaken at a funeral home.