Developer apps cydia launch release You Fade Me Up, This tweak works with iOS 8. You Fade Me Up jailbreak tweak brings fade-out visual effect to the application icons in the App Switcher for iOS 8 as you swipe up on your application preview cards to close them. The effect this tweak has on your device is completely aesthetic, but it seems like something Apple should have implemented in the first place. After installation no option to configure.
If you are interested, then you can free download You Fade Me Up iOS 8 from the BigBoss repository in Cydia. To install this program requires a jailbroken device (see if and how you can do the jailbreak to your iPhone by clicking here) and you need an Internet connection to download the package. This tweak is compatible with iOS 8.0 and later versions of the mobile operating system from Apple.