You are doing some long calculations on iPhone Calculator app, suddenly you make a mistake and then realize that there is only one way to delete the mistake by deleting the full number you just typed in. No more, there is a secret backspace function which lets you delete the single last digit.
Swiping right on the input screen will get rid of the last digit you just typed in. So now no need to pull your hair out when you make a mistake with your calculations on iPhone.
Here is a video if you want to watch this in action.