Group Size App for the iPhone?

Anyone know of anything that works like this for the iPhone? Seems like it would be pretty easy to make this software work with the built-in camera.

http://www.ontargetshooting.com/

Sorry, I do not know of any Ipod version software. Thanks for posting the question and linking the website look pretty simple to use and I have alot of question about a good software to use all the time.

I saw one in the app store (Shot Group Calculator), but the reviews said it was terrible and vitually useless.