Apple CEO Tim Cook Introduces IOS 8
Apple CEO Tim Cook introduces the IOS 8 operating system during his keynote address at the Worldwide Developers Conference in San Francisco, California Reuters/Robert Galbraith

Apple has stopped code signing for iOS 8.1 firmware after releasing the iOS 8.1.1 firmware upgrade. It means that those users who have upgraded their iDevices to iOS 8.1.1 will not be able to downgrade to any of the earlier version of the OS.

According to 9to5 Mac, since Apple has closed signing iOS 8.1 for compatible iDevices, the iOS 8.1.1 firmware is the most recent software version that users can upgrade or restore to. The source further states that if an iPhone, iPad or iPod Touch is currently on iOS 8.1, such users will not be able to downgrade to earlier editions of iOS if they upgrade to iOS 8.1.1.

Users, who are stuck on iOS 8 or iO7 or any of the previous build, will have to upgrade to iOS 8.1.1 if they wish to jailbreak or run the recent Cydia apps on their device. GSMArena states that IPSW Downloads, the famous third-party iOS firmware upgrade provider's database shows red exclamation marks instead of green check marks under 'Apple Signing Status' for iOS 8.1 build for all the compatible iOS devices.

The Cupertino company rolled out the iOS 8.1.1 update in November and it came with plenty of bug fixes and security updates. It supports iPhone 4S and later handsets, the iPad 2 and later tablets, the 5th gen iPod Touch and the 3rd gen Apple TV. The iOS 8.1 update was made available in October which brought new features like Apple Pay for iDevices featuring NFC chip, Continuity, Camera Roll and more.

Users, who wish to jailbreak their devices, will be content to know that jailbreaking iOS 8.1.1 is possible. TaiG, a Chinese developer known for jailbreaking iOS has recently a jailbreak for iOS 8.1.1. Currently, TaiG does not support all the recently launched Cydia apps and tweaks and it currently supports Chinese apps and tools.

NDTV claims that in the previous week Apple had declared that iOS 8 is running on 60 percent of devices. It further stated that 35 percent devices are running on iOS 7 only 5 percent of user are using the older versions of iOS.