Leak shows universal apps for both Windows and Windows Phone are coming
Microsoft is gradually traveling towards uniform Windows experience across all screen sizes - from phones through tablets to computers and larger displays. This, however, requires that developers be able to write one app, and only scale it slightly for the interface specifics on a a large or a small display.
It was rumored that with Windows Phone 8.1 Microsoft will be giving developers just that option, and leaked screenshots reveal how exactly the software giant is planning to merge WP, Win RT, and Windows Modern UI apps down the road.
As you can see in the slideshow below, Microsoft is clearly outlining the possibility for "Universal Store" apps, with a single effort aimed at both Windows Phone and Windows. The way this will be implemented is with 80% "shared solution", and just 20% differentiation for adapting the app interface to the phone or Windows computer realities with two Visual Studio projects. This will save a ton of work for developers, and will undoubtedly ensure a boom in their projects geared towards the Windows ecosphere.
Things that are NOT allowed: