Want to force close an app on iPhone? First, unlock your iPhone. If the phone does not have a Home button, for you, opening the app switcher is done simply by swiping your finger up from the bottom of the screen and then pausing in the middle. Those models which have a Home button, open the app switcher by double-pressing the Home button. The app switcher will reveal all the recently used apps as cards. Locate the app you'd like to close and then swipe its preview up until it has completely gone out of view. That's a force close of the app. If you'd like to reopen it from the Home Screen after, you can do that to fix freezing, crashing, or performance problems.