groov or the browser it is running in?
(Because you cant really ‘close’ groov, just the web browser it is running in).
From SSH (putty).
For Chrome:-
pkill chromium
From a touch screen? No. The whole point of the kiosk user in groov is that they can not exit the browser.
Make them a non kiosk user and you can select the ‘log out of groov’ option from the gear icon.