I recently posted a list of the VS2015 extensions I use on my main machine at: https://zoomicon.wordpress.com/2015/11/13/visual-studio-2015-extensions-i-use/ From that list of extensions I use the Productivity Power Tools one, it has a "Power Commands > Remove and Sort Usings" action that one can right click and run on the whole ...

Project Linker is a Visual Studio Extension that “helps to automatically create and maintain links from a source project to a target project to share code that is common to Silverlight and WPF”. In ClipFlair, where I have shared code between a Silverlight and a WPF project (I guess same would be for XNA projects [...]