FiftyThree, the developer behind the popular sketching app Paper, has posted a lengthy article examining the new Zoom feature that was added to Paper earlier this month. Zoom is one of those UI controls, like the color picker, that has grown so familiar as to become almost invisible. Designers drag and drop it out of a mental library of stock functionality, and the most pressing consideration is whether to use a magnifying glass or a +/- button for the icon. "Pinch to zoom" reinvented zoom for touch devices, and Apple made the gesture ubiquitous by including it in iOS. "Pinch to zoom" is now probably the single most broadly unde
