A minimal LightSwitch Shell that contains only Save, Refresh, and Design buttons. It does not contain a menu. It will automatically load the Default Screen.
You can read the walk-thru that covers the creation of the Shell here: http://lightswitchhelpwebsite.com/Blog/tabid/61/EntryId/68/Creating-a-Minimal-LightSwitch-Shell.aspx
The source code for the completed Shell (the version listed in the Visual Studio Gallery) is: