From Objectus Technology:
SaberFX is a program for adding Star Wars movie style special effects to your home movies using a process called Rotoscoping. Use it to add special effects including Lightsabers, Force Lightning, and Clashes. Add the effects to a home movie, then import into iMovie to finish the production.
MovieMator is a better all-in-one free video eidtor for Mac and it is also can add star effects to videos. MovieMator Free Mac Video Editor supports enhancing the video quality with one Chroma Key. Users are allowed to trim and crop fragments, cut footage into parts, delete unnecessary clips, rotate the frame, adjust the volume, import favorite music and add various filters / transitions in this professional video editing software for Mac.