The ALM rangers are unstoppable. Now they created a blog series about building your own widgets for the Dashboard in TFS 2015.
(For this screen, in case you have no clue: )
Here is the full series:
- Getting started with Widgets: http://blogs.msdn.com/b/visualstudioalmrangers/archive/2016/02/01/getting-started-with-widgets.aspx
- Developing the Widget: http://blogs.msdn.com/b/visualstudioalmrangers/archive/2016/02/01/developing-the-widget.aspx
- Issues and resolving them: http://blogs.msdn.com/b/visualstudioalmrangers/archive/2016/02/01/issues-and-resolving-them.aspx
- Publishing widgets: http://blogs.msdn.com/b/visualstudioalmrangers/archive/2016/02/01/publishing-widgets.aspx