Orsburn (Static Content)

Using Google Maps , a double-tap and hold on the screen allows zooming with a single finger by dragging it across the screen. That's tap once, then again quickly, but continue to touch the screen on the second tap.  Without picking up the finger, drag it across the screen. This was encountered by mistake on an iOS device running iOS 10.2.1 and Google Maps 4.28.91.  It may work on Android devices as well, and with older versions of Maps. Also, it's noted that this feature is probably detailed all over the Web.  But here it is again.