RevHeadz is an uncompromised engine simulation application that covers a wide variety of extremely realistic sounding car and bike engines – all of which are fully controllable by the end-user. RevHeadz for iOS is set for release in early 2014.
RevHeadz for iOS
RevHeadz Australian Release
RevHeadz is now live in Australia to test the water - https://itunes.apple.com/au/app/revheadz/id793064343?ls=1&mt=8