You want to improve your service? Watch yourself serving! With this app you can find your mistakes and correct them yourself.
The way it works is very simple: The app gives you a life view with an adjustable delay: You serve, then you watch your motion. Then you serve again and watch your motion again.
You don't have to press any buttons or any other steps to operate the app. It's like a mirror, but with the difference, that your mirror image is always delayed. The delay is configurable from 1 to 10 seconds.
Just watch yourself, what you did a couple of seconds ago.