One of the most prized new features of iOS 4 and on was the ability to run many apps at the same time and switch between them easily. One of the little issues with this is that when you close an application, it stays running in the background. Normally this wouldn’t be a problem. But contrary to popular belief, background apps take up a ton of battery life! By the end of the day, you could have every single one of your apps running in the background of your iPhone! Of course you can double-click the home button, tap and hold one of the app icons for a second, then hit the red circle in the top left. Then hit it again for the next app. And again. And again. And again. You’ll have to tap once for every single app that’s open. Done yet? Well, if you happen to be jailbroken, here’s a little tweak from Cydia that will help you. Open Cydia and search for KillBackground. Install the free package by Mathieu Bdard and respring your device. When your phone comes back, you won’t immediately be able to tell that anything is different. But open up a few apps, then double-tap the home button. Tap and hold one of the apps for 1 second, and voilà! You’ll see a little red crossbones icon in the bottom left. One tap and all of your apps are killed! You can also open up your settings app and select KillBackground to configure some different options. Enjoy!