iPhone X or later or iPad with iOS 12
- Swipe up from the bottom of the screen and pause slightly in the middle of the screen.
- Swipe right or left to find the app that you want to close.
- Swipe up on the app's preview to close the app.
 
iPhone 8 or earlier
- Double-click the Home button to show your most recently used apps.
- Swipe right or left to find the app that you want to close.
- Swipe up on the app's preview to close the app.