Airbitz & Libbitcoin Team Up to Create DarkMarket which looks to be an amazing working proof of concept.
They managed to create this in less than 30 hours of coding!

http://www.coindesk.com/airbitz-wins-toronto-bitcoin-expo-hackathon-darkmarket/

https://www.youtube.com/watch?v=lHVqH8XO1Pk

https://go.airbitz.co/airbitz-dark-wallet-win-bitcoin-hackathon-darkmarket/

Amazing work guys. Thank you, and keep up the good work.