Take a look at these tweets embedded below.
With Back Tap, you can perform various action by double or tripple tap on the back of your iPhone. Here’s one I set double tap to take screenshot. pic.twitter.com/uZKv4Cjorf— Aditya Daniel (@adityadaniel) June 23, 2020
At first blush, Back Tap seems wonderfully geeky but useless. Thinking on it some more, I can see some advantages but also some disadvantages as well. For example, would it be invoked easily, say while bumping around in a jacket or purse?