Shake to undo on the iPad. I just found myself giving my tablet a good shake to return a mistakenly archived email to my inbox. As Apple would (I’m sure) say: “Elegant in its simplicity, the shake to undo allows our users to have a truly innovative and even physical experience while undoing actions across the operating system.” This is a system-wide shortcut that seems to be the only way to achieve an “undo” in many situations. It’s not documented well, and I’m curious how many people even utilize it on their phones let alone their tablets. Gave me a good chuckle today when I did it on my 12.9” iPad without thinking.