I need an app that allows anybody to submit a post offering a food product for sale: the person (seller) must be geolocated and show up in a map, when his post is posted. The post will show the product , price and a few other info. A (potential) buyer that is walking around will open the app and will see who's around and what's offering - right there and then. If the client likes it , s/he buys the product, rings the doorbell and gets the product. Very likely the payment will work this way: upon clicking on the item a 10% fees will be charged on the buyer's paypal/card account (this fee will go into my account) and then the buyer will pay the rest directly to the seller.
The developer will build the app and the web-based backend (if needed)