Pinch/open gestures on Android

[MarkDeaton]

I built a simple one-layer "Hello World" app; it deploys to Android and runs well. I notice, however, that the pinch/open gestures invoke the corresponding zoom action only after the gesture is complete (no feedback occurs during the gesture to indicate what will happen).

Is this expected behavior, or am I perhaps not including a critical library or event handler?

Thanks.
--Mark