With SuperSlider, you can add icon to sliders of your Lock Screen that works when you tap the button next to “slide to unlock”, clicking it would unlock and automatically launch the app.
You get to choose the app that should be launched when you click the button next to slide across . From settings.app, you would be able to choose the application from a list of installed apps.
SuperSlider leaves some glitches to be fixed, but they may be just for a while. Right now, slider gets stuck half way when you move your finger away. Other than that, all seem to work well for a tweak that’s free on Cydia store from Bigboss repo.
Search for “superSlider” on Cydia, on your jailbroken phone.