Switch between apps
While using one app, you can easily switch to another.
Open an app from the Dock. Swipe up from the bottom to reveal the Dock, then tap an app. Favorite apps are on the left side of the Dock, and suggested apps—like ones you opened recently and ones open on your iPhone or Mac—appear on the right side of the Dock.
Use the App Switcher. To reveal all your open apps, swipe up from the bottom edge. If the Dock isn’t already showing when you begin to swipe, swipe long enough to display the Dock then the App Switcher. You can also double-click the Home button. To see more apps, swipe right. To switch to another app, tap it.
Swipe between open apps. Swipe right or left with four or five fingers. To turn off the multifinger swipe gesture, go to Settings > General > Multitasking.
Close an app. If an app isn’t working properly, you can force it to close. (Typically, there is no reason to close an app; closing it doesn’t save battery power, for example.) In the App Switcher, swipe up on the app. Then try opening the app again.