On an iPhone X or later, from the Home screen, swipe up from the bottom-left corner of the screen and pause slightly in the middle of the screen.
On an iPhone 8 or earlier, double-click the Home button to show your most recently used apps.
- Swipe right or left to find the app.
- Swipe up on the app to close the app.
- Go back to the Home screen and launch the app again.