While the iPhone 6 release date happening with Apple's WWDC 2014 edition on June is a long-shot, revelation of iOS 8 via the same event is almost certain and so are the fresh killer features for the iPhone 5S successor.

Business Insider suggests that the jump from iOS 7.1 to iOS 8 is at best incremental but the publication seems to concede that the tech giant's upcoming mobile operating system is stuffed with new features and capabilities that are worth the wait.

And thanks to Mark Gurman of 9to5Mac, nine new offerings of the iOS 8-powered iPhone 6 are outlined below:

Performance boost

The core goal for iOS 8, currently codenamed Okemo, is to make everything about the next iPhone prettier and faster, Gurman wrote. But more than the aesthetic concerns, it appears that Apple engineers are burning midnight oil to deliver a new mobile platform that is optimised with the high-end hardware stuffed inside of the iPhone 6.

Integrated apps

Talks about the iOS 7 last year have suggested that Apple would love the applications found on the App Store to communicate with each other seamlessly. Data sharing between apps would make it easier for users to jump from one iPhone function to another. Or as Gurman puts it - the iPhone 6 cam will shoot a pic and immediately, Facebook or Twitter would pop out to suggest uploading the image. More likely, iOS 8 will finally present this functionality.

Automatic message deletion

To decongest the iPhone 6 message inbox, iOS 8 will usher an optional setting that will automatically get rid of ancient message exchanges. For the sentimental, of course, who wants to keep memorable threads, there is an option to turn off the function.

LTE-powered phone calls

The iPhone 6 is essentially the best iPhone ever to come with loads of killer features but Apple is not losing sight of the device's basic use - facilitating phone calls that is. With iOS 8, the handset is likely to process incoming and outgoing voice communication via LTE network. This translates to high-quality chats using the iPhone. Gurman notes, however, that the features is service provider-dependent, meaning telcos will have to provide the infra for optimal enjoyment of the service.

Improved CarPlay

In iOS 7.1, CarPlay is enjoyed by connecting the iPhone 5S with the control module using a Lightning cable wire. Hopefully with the iOS 8 introduction, the pairing would be via Wi-Fi or Bluetooth protocol with additional cool driving features to boot, the 9to5Mac writer predicts.

Fresh Voice Memos interface

Voice Memos in iOS 8 will wow with a straightforward interface and as a result, users will surely appreciate the easier navigation and editing features - all thanks to the reconfigured look and control buttons.

Stand-alone iTunes Radio

As streaming music providers like Spotify and Pandora gain tremendous traction in the mobile device sphere, Apple guns to catch with its own radio application. Enter iTunes Radio that will be divorced from its mother iTunes platform. As a separate app in iOS 8, iTunes Radio will permit users to access music not on their device and listen to online radio shows.

Simplified notification alerts

With the iPhone 5S, iOS fans finally had a taste of the Android-like phone notification servings though there were observations that the feature was somehow a bit complicated compared to its Google counterpart. There will be enhancements to come in iOS 8 on this respect, which Gurman describes as more on simplification - both in looks and features.

More reliable Apple Maps

When it comes to mobile device navigational expertise, Google Maps remains as the name to be trusted, which is very true for both the iOS and Android universes. Apple is gunning to change that with the newly-improved Apple Maps in iOS 8, which Gurman expects to provide highly dependable directional data in real time. With the application, the iPhone maker wants to erase the humiliation brought by the iPhone 5 navigational app that cost Scott Forstall his job in 2012.

Healthbook

To combat the healthy menu that came with the Samsung Galaxy S5, Apple is likely to serve Healthbook with the iPhone 6 and iOS 8. Beyond monitoring blood pressure rate, the application will attempt to pave the way for a healthier lifestyle and save lives, of iPhone users that is, when necessary.

The iPhone 6 release date is predicted to take place as early as August or September 2014 or a few months after the recognised iOS 8 unveiling at the 2014 WWDC that kicks off on June 2.