The iPhone 6, prior to its release date this 2014, has most of its killer features previewed and likely confirmed as Apple unveiled this week the fresh mobile device capabilities packed with the iOS 8 via the WWDC 2014.

The same is true for the 2014 iPads that according to KGI Securities analyst Ming-chi Kuo will arrive early in the fourth quarter of 2014 as the iPad Air 2 and the iPad Mini 3.

So below are the core iOS 8 features that Apple fans can look forward to as this year's new iPhone and iPad builds start to slide out of the box:

Health

Rumours referred to this iOS 8 component as the Healthbook and before it became official, it was billed as an application that will help device users to closely track their key medical data and keep a healthy lifestyle in the process. While the actual name was a miss, the basic functions floated by earlier reports turned out as accurate.

With integration to HealthKit, MacRumors reported that Apple plans to redefine the health care industry with this new service, starting off in the United States.

Notification widgets

Finally, widgets will arrive come the next iPhone and iPad releases, thanks to iOS 8. However, the function will be confined, temporarily for now, at the Notification Centre. Users, BGR said in a report, will be able to place widgets within the Notification area with its behaviour extended too on third party applications.

Expanded Siri

Siri gets the bump up treatment on iOS 8 and the upgrades include real-time dictation that supports around 22 different languages, streaming voice recognition, Shazam integration as engine for music recognition and hands-free iPhone/iPad control that is triggered by simply muttering 'Hey Siri!'.

Family Sharing

With this new iOS 8 feature, up to six members of a family can enjoy the fullness of life in the iOS universe. One notable use of the feature is the sharing of a family credit card in buying goods at the App Store. "When a child attempts to purchase an app, an adult will get a popup on their own device asking them to approve the purchase," said MacRumors on its report that underscore the added security feature of Family Sharing.

Touch ID

Touch ID is virtually confirmed as an across-the-board deployment for iPhones and iPads this 2014. In the iOS 8 render, Apple has decided to open or partially share users' fingerprint data to third-party developers. This means that in the iPhone 6 or iPad Air 2, Touch ID will help secure and authenticate mobile device transactions that use non-Apple applications.

Wi-Fi call

One iOS feature that didn't get du attention at the WWDC 2014 but will surely matter to iPhone users is Wi-Fi calling or initiating and receiving calls outside of cellular networks. This means free calls and according to Apple Insider, U.S. telco T-Mobile has confirmed that Wi-Fi calls on iOS 8-powered iPhones will surely work with its existing infrastructure.

Messaging enhancements

In iOS 8, Apple is giving users more control when using Messages. Among the new features are the ability to mute notifications for group messages, recording and sending of audio/video messages using the app and gesture-prompted automatic sending of sound messages.

Touch keyboard upgrades

Typing on iOS 8 represents a big catch up with Android. QuickType will be on hand for smart or predictive typing and to really make its more Android-like, iOS 8 will allow the installation of non-Apple keyboard apps and first in line to take advantage of this opening is the incredibly popular Swype.

64-bit mobile gaming

Apple has totally embraced mobile gaming in iOS 7. Now in iOS 8, the function will jump into the 64-bit standard with Apple's introduction of Metal with its new mobile operating system. "With Metal, Apple hopes to replace the industry-standard 3D-graphics API (application programming interface) called OpenGL," CNET said in a report.

Metal will be the gamers' best friend, paving the way for the next-level of mobile gaming with the iPhone and iPad at forefront, the report added.