I'm happy to share a little side-project with the community -- Framed is a fullscreen browser for Windows, in the same vein as Frameless for iOS. If you ever need to prototype for Windows Phone, this finally lets you hide all the browser chrome.
The exciting part is that it also works on PC, Hololens, and Xbox (soon). You can design a windowed app experience that mixes with the real desktop or place windows around your room in AR.
This is just the start, check it out at http://westonthayer.github.io/Framed/ and kick the tires if you can. I think there's a lot of interesting directions to take it. If you have ideas (or find issues), add them to https://github.com/WestonThayer/Framed. Happy prototyping :)