The app, called ParkingAuction, claims that their app will actually reduce emissions by reducing the amount of time drivers circle around looking for a parking spot. That access comes with a price, because parking hunters must pay to know where the spots are.
From ParkingAuction's About Us page:
"Ever get caught in city traffic or waste gas trying to find a parking spot? ParkingAuction.com is a mobile web application that helps you find street parking by connecting people leaving a spot with people looking for spot through a real-time auction. By letting you realize the value of the parking space you are giving up, Parking Auction reduces traffic congestion, pollution, wasted time, money and frustration."
Currently, the site isn't using real-world cash, only credits.