Sounds interesting. How does it work in real life? Can I go to starbucks and buy a latte with my phone? How does starbuck know they got their money? How easy it

Sounds interesting. How does it work in real life? Can I go to starbucks and buy a latte with my phone? How does starbuck know they got their money? How easy it is for the customer? Type amount, receiver id (numbers only) and send? Tell me more...