Dartfish is a fantastic app for demonstrating correct technique, or identifying faults. Currently on sale for 99¢ on the Apple App Store.
From the developers:
Dartfish, which was used by over 40% of the medal winners at the London Olympic Games, has always been providing video analysis solutions to the world’s leading sports teams.
We now have an award winning video analysis app for IOS devices that is perfectly suited for all sports programs. It was featured by Apple in their keynote introduction to the ipad 5 and won the Tabby Award for best worldwide tablet app in the Sport and Fitness category.
Thanks to John Kessel for notifying us of this great deal.