Fastlock is a new modification to the lock screen that provides shortcuts to common actions is activated by double-clicking the Home button while your iPhone is locked. It is one of those features that we would bring the iPhone by default, but more customizable, it has no adjustments.
With Fastlock can make a call, write a message or email, a tweet, add a contact to our calendar, write a note, set an alarm or take a picture, and all this without unlocking your iPhone.
You can download for $ 0.99 in Cydia, you'll find ModMyi repo. You need to have jailbroken your device.