The Twirl effect distorts the video/image within a circular region. The pixels at the centre of the circle are rotated by a specified angle; the rotation for other pixels in the circle decreases with distance from the centre, diminishing to zero at the circle's edge. You can apply this effect as in/out animation to make your project even cooler.

A grid is a collection of horizontal and vertical lines creating a pattern against which you can line up your design elements. 

*At the bottom of the left panel on the dashboard screen.