This document discusses how gestures have revolutionized how people interact with their mobile phones and the apps that popularized these gestures. It outlines several iconic gestures like pinch to zoom, double tap, swipe left/right, and press and hold and the apps that helped mainstream their use, such as the iPhone popularizing touchscreens, Instagram using double tap to like photos, and Tinder implementing left and right swipes for matching. The document also notes some gestures that did not catch on as much and asks for predictions on what the next big gesture may be.