Jailbreak community always comes up with amazing tweaks that save’s a lot of time & quite useful. This tweak is one of such list of tweaks FastLock tweak will allow you to add shortcuts to your lockscreen such as the launch window to write a tweet, or take a picture, make a call, send an email etc. FastLock is available for 0.99$ on Cydia. You can goto into the settings ofyour device to determine which shortcuts you want on the locked screen. this is quick & fast way to access different quick tasks.
Offcourse You need to have Jailbroken iPhone for this tweak