Apple’s iOS 7 has finally been announced with much fanfare, and it’s the most radical update to the OS since 2007. The feature set is robust and the UI is refreshed, so let’s check out the biggest new features…Design overhaulIf there has been one consistent criticism of iOS in recent years, it was the outdated nature of the UI. The new version of the software seems to take care of that with a wide-ranging update of the old, largely skeuomorphic design. The stitching and green felt are gone for good. In their place are frosted glass effects, flatter icons, and more white-space in the UI. It is still recognizable as iOS, though.The interface uses the frosted glass look in a variety of apps to give a feeling of context and depth — Apple even used it in the background of the keyboard. Siri also gets a cleaner look with a semi-transparent UI.Control CenterAnyone that has ever wanted to go into airplane mode, or simply turn off WiFi knows how painful it can be to dig through the iOS menus searching for a toggle. The new Control Center is accessed with a swipe up from the bottom of the screen and contains a number of extremely useful shortcuts.There are toggles for WiFi, screen brightness, Bluetooth, and more. Also in Control Center are media controls, AirPlay, and some app shortcuts. It should have happened a long time ago, but at least Apple got it right this time.Real multitaskingA few years ago, Apple enabled limited multitasking in iOS, but now it’s taking a more Android-style approach by allowing all apps to run in the background. The system will actually try to determine which apps you need in the background all the time, and which can be closed. This is an attempt to save battery life, but to be truly useful it will have to be very good at figuring out usage patterns. Multitasking in iOS 7 also implements a card-style screen for app switching.This isn’t the kind of change that requires users to learn a new way of using the device, but it still improves the experience. That’s the best kind of change, when you think about it.iTunes RadioThis is an important feature mainly because Apple really needed to get a streaming service figured out to match the competition. Pandora, Spotify, and even Google beat Apple to the punch. Apple’s iTunes Radio will be free with ads for all iOS 7 users. Anyone with an iTunes Match subscription will get the experience ad-free.It will be built into the redesigned Music app and will support station creation, buying individual songs, and sharing stations. There don’t appear to be any defining features just yet. It’s not clear how much control users will have over tracks. For example, will iPhone users be able to cache songs offline? The service will roll out this fall in the US after years of anticipation.This is far from everything Apple changed in iOS 7, but these are the highlights. Sharing, photos, FaceTime, the App Store, and other features saw updates too. Developers will get access to the new beta software today, but regular users will have to wait for the official fall release.