show/hide top menu by swiping (one-finger) down/up
The only intuitive behaviour IMO to show the menu from the top bar, is to slide / swipe down using 1 finger (that part is semi-ok right now already, only the "tip" is recognized though) and to hide it again, swip up, starting basically anywhere, while it is open.
Nobody I showed it to would have guessed that the top-menu closes by tapping the top bar again.