Develop an iOS app that users can buy/sell/trade marketplace

General information for the app: trade marketplace Kind of development: New app from scratch Description of requirements/features: UK DEVELOPERS ONLY! Looking for a talented UK developer to create an app for my startup. Key Features: - Authenticate using Facebook log-in credentials or phone number verification (via Digitz) - List items- simply snap photos on mobile device to post items for sale - Items Newsfeed- discover and like items to buy or trade - In app messaging- communicate with other people to securely complete deals - Ability to call users Here is a similar app - less features required: https://itunes.apple.com/us/app/swap-club-sell-things-socially/id1121191485 Extra notes: