Apple , and some of them are designed to “fix” mistakes. While the Mac has the Command-Z command, the iPhone has its own unique way to fix a mistake: Shake to Undo. Shaking the device to undo a mistake has been around since 2009, back in iOS 3 (which was called iPhone OS at the time). And it’s one of the most underrated features of iOS.
Instead of an undo button or symbol on iOS, you simply shake your phone. For most iPhone users it's a forgotten feature, but writer John Gruber recently brought the feature to light, with an analysis and the revelation that it was actually originally designed as a joke.
In any case, it's a useful reminder that the feature exists: When you want to undo something on your iPhone, just shake it!
Shake to Undo is enabled by default. You can turn it off in Settings>General>Accessibility, but be aware that there is no other undo feature for iOS. Apps may have an undo button (usually a counterclockwise arrow), but the feature stops there.
In iOS 11 for iPad, Apple introduced undo and redo arrows for the keyboard, but it didn't extend them to the iPhone. Last year's software update also brought drag and drop.
With Shake to Undo enabled, iOS users can quickly undo an unwanted action, such as a mistake while composing a text message, deleting an email, or moving a photo to the wrong place. It's a universal way to fix any mistakes, something that Windows Phone and Android don't yet have.
So if you made a mistake you want to undo, just shake your iPhone or iPad. It might make you fall in love with this old-fashioned energy!
