iOS 7 is the most important refresh since the launch of the original iPhone, Apple has said.
The operating system comes with a new yet familiar interface, which is designed to make content take advantage of all available screen space. Seemingly this is acknowledging the fact Samsung's smartphones continue to grow in size, while Apple's largest, the iPhone 5, sports a four-inch screen.
* Control Centre is among the 'hundreds of new features,' providing users with access to Airplane Mode, wi-fi, Bluetooth, screen brightness and more. It's accessible with one upwards swipe from the bottom of the screen.
* Notification Centre is available from the lock screen to offer users an overview of their alerts. The new Today feature offers a summary of events for the day ahead, such as meetings and so on.
* Camera app features filters – a move BlackBerry made with BB10 – which will undoubtedly have been inspired by Instagram. Users will be able to make real-time photo effects and switch between four camera options with a swipe.
* Safari redesign supports full-screen browsing, while iCloud Keychain stores all passwords and credit card details securely across all devices.
* Siri has new male and female voices and Twitter search integration, so users can ask what people are saying on the social network. Wikipedia and Bing are also integrated.
* Music app comes with iTunes Radio internet steaming service, which features over 200 stations. Available across iPhone, iPad, iPod Touch, Mac, PC and Apple TV.
Developers can immediately access the iOS 7 beta software and SDK via developer.apple.com, while iOS 7 will be available as a free update this autumn.
Our sister-site Mobile Entertainment has more details.