The Slow Motion Smoother Effect makes your home-made slowed down clip look like a professional clip.
Unlike some other iMovie plug-ins, your whole clip will be slowed down. You will not loose the end of your clip.

To slow down a clip, iMovie duplicates each frame. The visual result is as if iMovie drew the next frame after a longer period of time compared to a real-speed clip. This doesn't give a flawless playback. The Slow Motion Smoother Effect fills the gaps between two frames, making your clip playing flawless.

Click here to learn more about the Slow Motion Smoother Effect.