Good evening.
It'snt a shortcut, but it's also exist a tip to close apps directly before the Liberkey closes.
Liberkey Tools >> Configuration >> AutorunCheck
Enable Autorun and
When Liberkey closes.
Drag and drop your app' shortcut in the bottom of the windows
(If you want you can modify the delay and the order if you have some apps in it).
Apply the change before closing the windows.
Enjoy.
N.B. : It's also possible add an app in these Autorun menu with a
right click on the app => Shortcut properties => Advanced => Autorun => On shutdown if not already runningJP4U