With a click begins the count of time, the time count will always appear in the foreground even if you move to another app or go to the Home screen.
One Click: Start / Pause
Two Click: Stop
Long Click: Reopens the Main App.
From the Primary App you can turn off the Flying Timer by clicking on the Red X.
While you can reduce the app in hidden mode with the button on the top left. In this case the timer will remain active.