From google maps on my one plus. Menu > "Tips and Tricks" > "Zoom in and out in more ways than one." I didn't know about it either, but it took a minute to fin

From google maps on my one plus. Menu > "Tips and Tricks" > "Zoom in and out in more ways than one." I didn't know about it either, but it took a minute to find the how to explanations. Personally I prefer standardized gestures to buttons to save the screen space, but thats just me.