How to create and effect similar to the "slice" on Fruit Ninja?

scrapee_net

I'd like to know if can someone help me to create a similar effect to the one as seen in Fruit Ninja. Where if you touch and drag the screen, the "slicer" will follow the finger. And if you just touch somewhere without dragging, nothing happens. Deep blue apps has a template very similar to fruit ninja, but the slicer is different.

Can someone give me some tip?

App Surge

There is a great demo for this in the "New" section of the GameSalad creator.

scrapee_net

how is it called?