I need a mobile app developer

I need an app called BazaarCo that will provide a simple and easy way to allow gamers all over the world to buy or sell their gaming equipment such as consoles, PC monitors, controllers, cables, PC parts, keyboards, gaming desks, gaming chairs or anything related to the gaming community within a 1000 km radius form their position or in/near their city. A user should be able to post adverts for free, with all the relevant information about the product, on the app with their own profile to view their posts and any other posts they have saved to view later and should be able to message the person in the app and organise the sale.