Grabby is a great tweak developed by Ryan Petrich famous that just landed in beta on Cydia.
In fact Grabby will allow you to use the camera icon at the bottom of lockscreen to launch the Phone application, SMS, Music and Camera.
From there, you can choose which applications to throw(launch) quickly. Once once that is done, go on the lockéen, put the finger on the shortcut of the camera which if also names(appoints) "to grabber " then make slide your finger towards the left and there, move on the icon of the application that you want to throw(launch) then to slide the finger upward "to lift"(raise") Lock screen.
Attention, the tweak is in version 0.1, thus its very first, it contains some bugs, and if you have a theme on Lock screen which changes the icon of the shortcut this one will become again as originally.
Grabby is available on the repo http://rpetri.ch/repo/