DriveGain is a interesting iOS app which promises to cut your gas bill by 15 percent.

The application, which is currently available in the App Store for $5.99, does this by teaching users to drive more efficiently. As a result, users of DriveGain reportedly emit less carbon dioxide which makes them “greener” drivers.

According to the app’s release notes, users of the application in the US will save an average of $205 in a year. UK users will save £170, while EU users will save €175. The app’s developers note that “on this basis, the application should pay for itself within two weeks.”

Furthermore, while DriveGain previously only supported manual transmission vehicles, the latest version brings support for automatics. If you want to find out more about this interesting iOS app, check out Cult of Mac’s interview with DriveGain CEO Simon East.

Alternatively, you can take a look at DriveGain in the App Store, where it’s currently priced at $5.99.