Based on tapping detection technology, TapMagicPlayer let you control video playing without touching the screen of your smart phone.
Here is the demo:
http://www.youtube.com/watch?v=uMJtmbJmHO8
While playing videos, tap the left side of the device to step forward for a few seconds; tap the right side to step backward for a few seconds; double-tap the back side to play/pause the video.