After experimenting with various onscreen indicators for swiping, I decided I just didn’t like it. On certain resolutions the screen was just too crowded. I even experimented with putting indicators on the side. Still it seemed too much. So I decided to just remove them.
I did replace the pinch/zoom code with the swipe up/down code and liked the results. But I may wait until I port the whole code base to Unity before I post another update.