Many developers had trouble using Gaussian blur as an overlay when iOS 7 first came out. It was kind of unintuitive — you had to snapshot a view, apply a filter to the image and then add this image to the view hierarchy, for example with the UIImageView. It’s gotten better in iOS 8, thanks to UIVisualEffectView. Unfortunately, creating custom UIVisualEffect subclasses isn’t documented, so I (Arkadiusz Holko - N.I.) had to use the old-fashioned way to create the motion blur effect.
An objective-C API that uses the new iOS 7 UIView snapshot category drawViewHierarchyInRect:afterScreenUpdates: to produce Apple Notification and Control Center like blur effects. 7blur supports both live real time and static blurred backgrounds enforcing UI depth.
Fleksy is an alternative keyboard for iOS that I first tested when Launch Center Pro, an initial partner, implemented it a few months ago. Within the limitations of iOS, Fleksy provides a different typing experience that can be faster than Apple's default keyboard.