Jack Dorsey Mobile Payment system.
original key distinguishing feature: free Credit Card-scanning dongle that attaches to a Mobile.
For Free Agent-s who don't already accept Credit Card-s, and don't have a fancy Point Of Sale system to integrate into.
Dec'2010 - got $27M at valuation of $240M!
Oct'2013: launches Cash service - like PayPal but with no fees, and goes directly from bank to bank.