Apple will roll out iOS 8 on 17 September

Apple has announced that the next version of its mobile operating system, iOS 8, will be available for free on 17 September – a week today.

You'll be able to upgrade to the eighth version of iOS on the following devices: iPhone 4S, iPhone 5, iPhone 5C, iPhone 5S, iPod touch 5th generation, iPad 2, iPad with Retina display, iPad 3 ('the new iPad'), iPad 4, iPad Air, iPad mini and iPad mini with Retina display.

In other words, iPhone 4 owners won't be able to make the jump (or those with older iPhones, obviously), and original iPad owners.

Apple also said that its new payment system, Apple Pay, will go live in the US in October with the iPhone 6 and iPhone 6 Plus as a free update – but the company didn't mention an availability date for the UK.

iOS 8 includes a shed-load (or possibly a boat-load – or maybe somewhere between the two) of new features, with a new predictive QuickType keyboard, overhauled Messages and Photos apps, and a generally slicker and more intuitive UI.

There's also a new Health app, as was promised, and the HealthKit and HomeKit frameworks for fitness and smart home stuff aplenty, with the OS encompassing over 4,000 new APIs for developers.

Related: How to upgrade your iPhone 5s to iOS 8: Before the official release

Craig Federighi, Apple's senior vice president of Software Engineering, commented: "We're excited for hundreds of millions of users to begin experiencing iOS 8, with incredible features that offer new ways to use your iPhone, iPad or iPod touch. iOS 8 also creates an extraordinary environment for developers, providing them the ability to create amazing new apps like never before."

Family Sharing is also being introduced with iOS 8, which brings a shared family photo stream and calendar into the mix, and iCloud Drive which allows for syncing across iOS, OS X and Windows devices, and collaborative features with the ability to work on the same file via multiple apps.