When you are buried deep in an app, and you want to go back to the app’s main screen, in a lot of cases you just need to keep tapping on the button in the upper left-hand corner. Each tap brings you back to the previous screen. A good example for this is the Settings app or Files app. Apple introduced a new was to go back through this ‘stack’ with iOS 14, you can now just long-press or tap and hold on the button in the upper left corner to bring up a menu. This menu shows you the history or stack of the app. Just select which screen you want to go to from there! See how to navigate an app’s history stack in this video for the iPhone.