Windows Phone 8.1 is the precursor to an OS that will “rule them all”

Microsoft is inching closer to merging Windows Phone 8.1 with Windows RT if a software development kit [SDK] based on the upcoming version of its smartphone OS is to be believed.

Related: Windows Phone 8.1 screenshots show revolutionary notifications menu

A Reddit user cited by The Verge posted details about the SDK and it showed there would be support for “Universal Apps” that let developers work on apps that are near identical across both Windows Phone 8.1 and Windows 8.1

Developers will be able to work on Windows Phone Store and Windows Store apps that use the same shared HTML and JavaScript code thus creating apps that are almost exactly the same.

Further to this, Windows Phone 8 apps will now use the same .appx packaging that is used to distribute Windows 8 apps and whilst it doesn’t guarantee full integration across the phone and desktop just yet, merging is clearly a priority.

Multitasking has also been given a slight tweak as developers commented that the back button doesn’t terminate the application but lets it run in the background much like is the case with Windows 8.1.

Two features that aren’t present in the new version of Windows Phone 8.1 are the Siri-esque Cortana personal assistant as well as the company’s new notification centre, Action Center, which are both shrouded in secrecy at the current juncture.

Other features include a “Battery Power Sense” feature to monitor and track battery life as well as a “receive texts using” setting to control the default messaging application and SkyDrive has been rebranded as OneDrive across the OS.

Music and Video apps are separated into distinct apps and the camera app has been changed so that the style closely resembles Nokia’s camera application. iCloud accounts can now be added on to Windows Phone 8.1 and the browser has been upgraded to Internet Explorer 11.

Related: Cortana voice control tipped for Windows Phone 8.1

It’s expected that Microsoft will show off Windows Phone 8.1 at Mobile World Congress in Barcelona later this month when Nokia will release three smartphones that will have the new OS.