Compatible with iOS 8
This tweak is designed to give you the option to select certain keywords or certain apps which will not be allowed on the lock screen.
For example, if you flag the keyword "foo", any notification sent to your phone with "foo" in its content will be replaced with "sensitive content hidden" on the lock screen.
If you choose to black list, say, Messages, all Messages notifications content will be replaced with the aforementioned text.
Source code available on Github