Grumpy Old Geeks Products Currency Product Currency 2 mentions in 1 episode Currency is the name used in the discussion for a retailer-backed mobile payment system that uses QR codes. Mentions 82: I Can Haz Ubercorn? Oct 31, 2014 28:26 It’s called Currency. 30:02 It uses QR codes and cameras to go back and forth to get the payment token.