Visual Studio 2015 has plenty of UI improvements and UI debugging features. It has a great Javascript editor and Visual Studio emulator for Android. Many more other features which I also need to dig into.
Go and get it here: Download Visual Studio 2015 CTP 6
Update:
See the Visual Studio Features Timeline here:
https://www.visualstudio.com/en-us/news/feature-timeline-vs
Update:
See the Visual Studio Features Timeline here:
https://www.visualstudio.com/en-us/news/feature-timeline-vs