As you use apps on your iPhone or iPad, your App Switcher begins to accumulate a running history of recently used apps in the order you’ve use them. These apps are suspended in a frozen state to make multitasking more efficient, but even suspended apps use some of your handset’s RAM to make relaunching them faster.
iOS automatically manages your device’s memory to ensure smooth operation, but if you’re a RAM nut then you may habitually force-close all your App Switcher’s suspended apps when you finish using your device. QuitAll is a newly released and free jailbreak tweak by iOS developer Dave van Wijk that lets you do this in one fell swoop as opposed to swiping up on each of the App Switcher’s individual app preview cards.