Multitasking, iPhone Style
Instead of offering conventional multitasking, the iPhone uses something Apple calls Fast App Switching. When you click the Home button to leave an app (or swipe up on the screen of an iPhone X or newer) and return to the Home screen, the app you left freezes where you were and what you were doing. The next time you return to that app, you pick up where you left off instead of starting over.
Do Suspended Apps Use Battery, Memory, or Other System Resources?
Apps that are frozen in the background do not use battery life, memory, or other system resources. For this reason, force-quitting apps that aren’t in use does not save battery life. In fact, quitting suspended apps can harm battery life. There’s one exception to the rule that suspended apps don’t use resources: apps that support Background App Refresh.
In iOS 7 and up, apps that can run in the background are even more sophisticated. That’s because iOS learns how you use apps using Background App Refresh. If you usually check social media first thing in the morning, iOS plans for that behavior and updates your social media apps a few minutes before you normally check them to ensure that the latest information is waiting for you.
Apps that use this feature run in the background and download data when they’re in the background. To control Background App Refresh settings, go to Settings > General > Background App Refresh.
Some iPhone Apps Run in the Background
While most apps are frozen when you’re not using them, a few categories of apps support conventional multitasking and run in the background (for example, while other apps are also running). The types of apps that can run in the background are:
Music: Listen to the Music app, Pandora, streaming radio, and other music apps while doing other things. Location: Both Apple Maps and Google Maps allow you to get directions and use other apps simultaneously. AirPlay: Apple’s technology for streaming audio and video from the iPhone to compatible TVs, stereos, and other devices runs in the background. VoIP (Voice Over IP): Apps such as Skype that make phone calls over the internet instead of over a cellular network work with other apps. Push Notifications: These notifications let you know something’s happened in another app that you may want to check out. Apple News: Content in the Apple News app downloads in the background to ensure the latest news is waiting for you. Bluetooth Accessories: When Bluetooth accessories are paired to your iPhone, data may be sent back and forth. Background: The Background App Refresh feature updates certain apps while they’re not running.
Just because apps in these categories can run in the background doesn’t mean they will. The apps have to be written to take advantage of multitasking — but the capability is in the OS and many, maybe even most, apps in these categories can run in the background.
How to Access the Fast App Switcher
The Fast App Switcher jumps between recently used apps. How you access it depends on the iPhone model. On iPhone 8 and earlier, double-click the iPhone Home button. On the iPhone X and newer, swipe up from the bottom of the screen (this gesture has replaced the Home button on these models, among other gesture-based shortcuts).
In iOS 9 and up: The screen drops back a bit to reveal a carousel of screenshots and app icons for your current apps. Swipe left and right to browse apps, then tap the app you want to use. In iOS 7 and 8: The experience is similar to iOS 9, except that instead of a carousel, there’s a flat row of apps. Shortcuts to frequent contacts appear at the top of this screen. Otherwise, it works the same way as in iOS 9. In iOS 4–6: Most of the screen is grayed out and reveals a set of icons at the bottom. Swipe the icons left and right to see recent apps, then tap an icon to launch that app.
On an iPhone 8 series, iPhone 7 series, and iPhone 6S, the 3D Touch screen offers a shortcut to access the Fast App Switcher. Hard-press the left edge of the screen to access two options:
Swipe left to right to switch the last app you used. Hard-press again to go to the Fast App Switcher.
How to Quit iPhone Apps in the Fast App Switcher
The Fast App Switcher also quits apps, which is especially useful if an app isn’t working properly. Quitting third party apps that are suspended in the background stops them from functioning at all until you relaunch them. Quitting the Apple pre-installed apps allows them to continue with background tasks like checking email, but forces them to restart.
To quit apps, open the Fast App Switcher, then:
In iOS 7–12: Swipe the app you want to quit off the top edge of the screen. The app disappears and quits. Quit up to three apps at once by swiping them at the same time. In iOS 4–6: Tap and hold an app icon until the icons begin to shake and a red badge with a minus sign in it appears on the apps. Tap the red badge to quit that app. You can only quit one app at a time.
How Apps Are Sorted in the Fast App Switcher
Apps in the Fast App Switcher are sorted based on what you used recently. This arrangement groups your most-used apps together so that you won’t have to swipe too much to find your favorites.
