Need iPhone App Built from Ground Up - Functionality and Graphics

I need a team with proven success in developing iOS apps to create a new universal app from the ground up. We have the idea / concept and need a team to put together the app so that it is functional and contains the needed graphics / icons. Our app is a social app that connects other users of the app and allows one person to post jobs in their location while others who are near that location can claim the job. Thus, the app should use GPS to show locations on a map while people can browse the map and claim jobs. The app will need to have an interface that allows sellers to post their jobs and set details such as pay, while workers can claim jobs. We also need a rating so that the workers can be rated by the person who posted the job. There will also need to be in-app upgrades as those who wish to bid on jobs will buy bid packs. Graphics are not intense as this is not a game, but a utility, however, we want it to look professional for the navigation buttons, home screen, as well as the map, etc. Further details regarding specific functionality will be given to qualified bidders