"iOS 7 is the biggest change to iOS since the introduction of iPhone," CEO Tim Cook told the conference. "It's packed with tons of new features, and a stunning new user interface."
As predicted, the first look at the new interface shows that Apple under Jonathan Ive has gone a long way down the minimalist, flat design route, although the design is not totally free of gradient or flourish. It's essentially an evolution of the look that at first glance looks fresh and modern while still recognisably iOS.
The icons have been redesigned with a new palette of colours and all the elements, including the surrounding chrome, look flatter. Layouts are clean, the signal bars have been replaced with a series of dots, and there's a new slide-to-unlock function.
But iOS 7 isn't just about simplifying the look of the system. The new OS uses the accelerometer to adapt the screen in parallax, creating a 3D feel that looked very impressive in the demo. And while the introduction of Helvetica Neue Ultra Light - a slimmer variation on iOS's standard Helvetica Neue font - made us worry about readability, the good news is that the icons and background in iOS 7 adapt to the available light to improve readability.
iOS 7 will be rolled out "in the fall", we were told. Here are a few more glimpses of the new UI to whet your appetite...
For full details of Apple's announcements at WWDC, check out this article on our sister site Tech Radar, or watch this video roundup:
What do you think of the new look for iOS? Share your views in the comments below!