Evoke iPhone App

We are leading Western Australian out-of-home media supplier and require help building a simple iPhone/iPad app to show case all 19 or so media offerings. It may also ne noce to incoporate simple interface so say if user selects 18 to 24 years olds icon it brings up what media is suitable, then from there user can simply browse pics of different media to give them ideas on future advertising/ marketing campaigns. Other work may be available on application.