Image: Apple

Apple has pulled the switch on its latest mobile operating system, iOS 8.1, for iPhones and iPads.

The Cupertino, Calif.-based technology giant released its debut version of iOS 8 in September following the iPhone 6 and iPhone 6 Plus launch. Since then, the company has been working on bringing the full bevy of features and functionality to its devices.

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Some users were left frustrated, however, that not all of the final billed features would arrive — first until its desktop operating system counterpart OS X Yosemite was released , and secondly until iOS 8.1 was released.

iOS 8.1 is available on iPhone 4s handsets and later, iPad 2 tablets and later, and iPod touch fifth-generation devices and later.

Users can update over-the-air or through the latest version of iTunes.

No doubt the flagship feature of iOS 8.1 is Apple Pay, which allows users of the latest iPhone 6 and iPhone 6 Plus to use their devices as wireless wallets, both in-store and online.

Apple touts the service as the "wallet, without the wallet," allowing its latest iPhone users to simply tap-and-pay through contactless payment technology.

Although slow to adopt near-field communications (NFC), Apple finally bit the bullet and included it in its latest smartphone line-up. It also works with its Touch ID fingerprint technology, adding an additional layer of security.

While NFC is not included in the latest iPads announced earlier this month, iPad users can still make online payments through Apple Pay.

Apple has partnered with hundreds of banks and more than 220,000 participating stores, including Duane Reade, Bloomingdales, McDonalds, and Whole Foods, with more landing in the coming months.

But the new iOS 8.1 update isn't just limited to mobile-only users. Updaters using the wider Apple desktop and notebook ecosystem will also see a new functionality, which Apple dubs Continuity.

Continuity bridges the gap between your desktop or notebook Macs, and your iOS-powered mobile devices. Its flagship offering, Handoff allows users to seamlessly pass work on from one device to another. Handoff was released alongside the launch of OS X Yosemite.

iOS 8.1 also adds more functionality to narrow the gap between the two sets of devices.

Now included in the software update, SMS Relay allows traditional text messages to be sent and received from your OS X Yosemite-powered Mac. Before, only Apple's own iMessage system, which uses data rather than the cell network, would work from the Mac.

Also, Instant Hotspot kicks into action by providing your OS X Yosemite-powered MacBook with cellular network when your notebook can't find a Wi-Fi signal.

The long-loved "Camera Roll" also makes its reappearance, after being banished to the trash can in the original iOS 8 update. Apple executive Craig Federighi highlighted the return of the Camera Roll at its October media event as something that customers missed, and wanted back.

Adoption so far of iOS 8 has been slow and stunted, with Apple hoping the full feature set will spur on growth.

As of October 13, about a month after iOS 8 was released, it had eeked to just 48 percent usage across its iPhone and iPad range, just up 1 percentage point from a week prior .

Many held off from upgrading because of the storage size of the upgrade, which meant deleting items from their devices. Many others refrained from jumping to iOS 8 because of reported issues with iterative updates .