Apple's iOS 8 is expected to be announced at Apple's WWDC conference later today after the company confirmed that developers from around the world will learn about the future of iOS at the annual conference in San Francisco. A banner has even been spotted in the venue.

So what can we expect from the latest version of the mobile operating system for the iPhone and iPad? We've searched high and low to bring together all the iOS 8 rumours, gossip and everything we know so far so you've got it in one simple go to place. We will be updating this article as we discover more information, so read on and sound off in the comments as to what you think Apple might (or might not) have in store for iOS 8.

iOS 8 WWDC announcement

Apple likes to use WWDC (pronounced dub-dub-dee-see) to announce new features coming to the mobile OS during its keynote and we suspect this year will be no different.

By detailing some of what's possible - usually the expected headline features - it gives developers plenty of time to look at how the new features work, but also so they can discuss them with other developers across the week at the show.

iOS 8 Healthbook

Rumours and speculation so far suggest a strong push towards letting iPhone users better track their fitness with the introduction of an app called Healthbook. Taking on board the huge boom in wearable fitness trackers, Apple has quietly been getting ready to allow you to treat your phone as a fitness tracker without having to buy an extra device (or maybe that will be the iWatch).

According to a range of different sites, sources, and "people familiar with the matter" the Apple Healthbook app will let you monitor a number of "vital stats" as well as double up as a fitness tracker pulling in data from the iPhone 5S M7 motion processor.

Depending on where and what you read those vital stats range from monitoring hear rate, blood pressure, sleep tracking, oxygen saturation, and even blood sugar tracking - ideal for diabetics.

Although it is not entirely sure how Apple will be able to track all of these features, a lot are possible already with a number of apps in the App Store letting you track your heart rate or the steps you take using the camera and the M7 processor.

iOS 8 Maps

Although constantly improving, Apple still has to try and woo all those users who were disappointed and then promptly defected back to Google Maps in 2012.

Again, based on speculation, Apple is expected to announce new features and details for Maps in iOS 8 including public transport directions.

Apple acquired a few mapping companies in 2013, such as Embark, HopStop, WifiSLAM, and Locationary in 2013, and their technology is expected to bolster Apple Maps with mass transit, crowdsourced location data, indoor mapping, and more features. How wide-reaching that data roll-out will be, is yet to be seen.

Apple does have a tendency to stick to major cities to start with rather than a global rollout from day one, and with granular "data sets" like public transport, we would be surprised if the features weren't restricted to just a handful of major US cities like New York and San Francisco and possibly London.

iOS 8 Notification Center and other tweaks

Most of iOS 8, including the Notification Center, is expected to be simplified as Apple continue to hone the OS and take into account its findings of using the operating system day-to-day for the last year.

We've already seen that Apple is happy to do this with plenty of changes in iOS 7.1 showing that the company is refining the user interface all the time.

Other changes currently being rumoured are a move by Apple to allow CarPlay users to ditch the need of a Lightning cable (i.e. connect wirelessly) and Game Center being dumped altogether in favour of the details going into games instead. Does anyone use it anyway?

iTunes radio, still only available in the US, is also expected to become a separate app to break it out of being lost in iTunes.

iOS 8 Mobile Payments

Apple allegedly wants to develop a new mobile payment service, though it is unclear if such a service would launch alongside iOS 8.

The Wall Street Journal reported that Apple's new mobile payment service would allow consumers to use their iPhones to purchase physical products instead of just digital goods like apps, songs, and other content via the iTunes Store. It would also work with Apple's Touch ID fingerprint scanner in the iPhone 5S. Tim Cook, chief executive officer at Apple, has previously said that Touch ID was developed with the hopes of one day using it for mobile payments.

iOS 8 iCloud

With apps like Microsoft Office and Google really taking advantage of the cloud to save files to and from your iPad and iPhone, Apple has to make sure that its iCloud service says relevant. At the moment, to access iCloud files you have to be in the specific app; like Pages for example.

iOS 8 Siri

Apple is largely expected to improve its mobile voice assistant - called Siri - in iOS 8 and now that Microsoft is stepping into the game with Cortana for Windows Phone 8.1 the pressure to make Siri even better is even stronger.

Apple wants to improve Siri’s search functions and feature capabilities. At the moment Siri is incapable of completing basic tasks like booking a vehicle or hotel reservation or using Apple's messaging app apart from sending text messages. But all that could change with iOS 8.

Apple is allegedly developing a feature set for Siri that would allow the voice assistant to do such tasks. Plus, Apple plans to expand Siri’s integration with third-party apps in iOS 8. Apple has existing partnerships and deals with companies such as OpenTable and WolframAlpha, but the Cupertino-based company wants to enable third-party integrations that do not require such partnerships.

Rumours are being fuelled even more by confirmation that Apple has bought voice recognition company Novauris.

Novauris started working on voice recognition tech back in 2002 when core employees of dictation specialist Dragon split off to start their own venture. These were mainly R&D members so the software they have been working on all these years is key to improving Siri's intelligent voice recognition and understanding.

Apple is also reportedly working on greater Siri integration across third-party apps. This is something Microsoft launched Cortana with the ability to do, like controlling Facebook from a simple voice command.

iOS 8 release date

Judging by previous release patterns, iOS 8 will most likely release in autumn 2014 alongside Apple's next generation iPhone (presumably called iPhone 6) or even iPhones.