App shop app

I want to create a app that people can take snapshot and tag with information with the picture, for people who want to sell the goods in the photo. Simple and easy for people who want to sell some stuff with their mobile phone. E-shop function like delivery option, payment option etc is necessary. May need some input for how to attract people to use this app. Any idea to connect with people interest to the seller's goods. Maybe we have several product catalog to choose when the new user signup then we propose the goods with their interest?