Need an iPad app to gather gas pump info and car milage for mpg calc?

I want an iPad app. I can not locate what I want at the iTunes place. How can I stimulate the iPad development community to create the app I want?
I want an app that will automate the information from a gas purchase and enter this info into a mileage calculation app.
Maybe this would require some coordination with Chevron and the others, and too, an auto manufacturer. Maybe this could earn some money for someone. I just don’t want to enter gas price, gas quantity and my car mileage to track my auto mileage.
Possibly an iPad camera could “see” this info on my car’s instrument panel and scan it from the pump’s display.
Seems so obvious to me that I assume such an app is available.
So, where is it? Or, how do I find it? Or, how can I get it on the app store shelf?