Apple have only just released their last update, but already they're on to the next big thing: iOS 8.

The last operating system saw a complete revamp of the iPhone, with more colours, new tones to take pictures in, new buttons and a complete overhaul of the notification and settings centre.

With this in mind, it's unlikely Apple will be bringing more materialistic changes this time around, with experts suggesting the update will be more app specific with a big focus on integrating health and fitness to the phone.

It is likely Apple will reveal the new OS at its Worldwide Developers Conference next month, meaning the software, and probably the iPhone 6 will launch together - with rumours of an early August launch.

1. The Healthbook app

According to rumours, Apple are planning to launch a Healthbook feature on iOS 8.

The app will collect data such as heart rate and daily activity all from your handheld device.

This would come as no surprise, given the recent craze for health and fitness gadgets, such as the Samsung Galaxy gear smartwatch and the rumoured iWatch.

Healthbook is expected to have a similar face to Passbook, but will have the power to track steps taken, distance travelled, calories burned, with some experts going the extra mile and even predicting hydration level and blood sugar tracking.

2. A more sophisticated Siri

Experts are rooting for a smarter personal assistant this time around, ideally one that understands what you're asking for, and doesn't get confused.

There are also talks that Shazam will be embedded into the new Siri, allowing you to ask what song is currently playing without having to open the Shazam app.

3. iTunes Radio and HD audio

Apple are apparently working on a reinvented iTunes Radio, however this time, it will be a separate app rather than hidden within the current Music app.

With everything now available in HD, Apple are also having to step up their game, and according to rumours, they are, with HD audio for iOS 8.

We're guessing new audio would mean new headphones, unless of course, the new feature links into the billion-dollar Beats and Apple buyout - in which case, beats users would be fine.

4. iWatch connection

No-one knows what's happening with the Apple iWatch, but if it's to be released soon, it would have to be compatible with the new iOS.

The Watch Utility app has also appeared in a series of leaked images from phones website Phone Arena, which also shows Healthbook, iTunes Radio and other applications such as Preview, TextEdit and Tips.

5. Split-screen apps

This one sounds really futuristic.

The latest iphones can just about do anything under the sun, with a phone that is, but one feature it's missing is the ability to have two apps running side by side - with a split screen, similar to Microsoft's Surface Pro 3.

Experts at Apple news website 9to5Mac have gone one step further, by claiming that apps may be able to interact with one another after the iOS 8 launch.

So you may be able to drag an image from one app to another, sooner rather than later.