This tweak will let you blacken your screen instead of going to the lock screen.
If you ever wanted your iPhone, iPad, or iPod touch to simply dim its display to a black state instead of locking itself after the set time in your Settings application - then this tweak might be for you. It has been dubbed Dim To Black Screen
and instead of auto-locking, your iPhone, iPad, or iPod touch will simply auto-dim. It was created by iOS developer Manvir