Use Shortcuts to automate things on your iPhone and iPad. Includes step-by-step instructions for making a shortcut that reminds you to charge your iPhone when the battery falls below 50%.
How to make and use Shortcuts in iOS
How to use the Back Tap feature in iOS 14
iOS 14 introduces "Back Tap," allowing you to perform actions with a double-tap or triple-tap on the back of your iPhone-- even in a case.