While iOS 8 allows apps to "run" in the background, many of these tasks are optimized to save battery life and improve performance. Those looking for true multitasking capabilities may be interested in Watchdog Pro. This tweak gives iOS apps the ability to fully run in the background, just as if they were still running in the foreground.
The jailbreak tweak DockBar makes launching specific apps a breeze from anywhere in iOS 8. The customizable app launcher bar can be invoked using an Activator gesture, which provides speed and efficiency for often-used apps. The DockBar interface will appear right in front of home screen icons or running app windows.
iPhone jailbreakers looking for a new way to invoke an Activator action can grab ProximityActivator. This jailbreak tweak adds a proximity sensor swipe to the list of possible gestures in Activator. Once the gesture is assigned to an action, the action can be invoked by simply moving a hand or finger over the proximity sensor. This means no touching or swiping the display at all.
Normally unjailbreaking an iPhone requires updating to the latest stock version of iOS. In cases where the new version of iOS cannot be jailbroken, this restricts options for users looking to reset their devices without an update. Thanks to @saurik iOS 8.3 and iOS 8.4 can be unjailbroken without updating the firmware with the tool Cydia Impactor. Once installed, this tool makes it possible to return the current iOS version to stock iOS by directly removing the jailbreak from the device.
The tweak Roundification brings a sleek look to several places in the iOS interface. Once installed, normal corners on notification banners and on the Notification Center itself are converted into a rounded style. These curves can also be applied to cards in the app switcher, and there is a rounded Dock feature for the home screen.