Boston-based mobile payment start-up Loop was founded in 2013 by Will Graylin and George Wallner, two very smart guys who figured out how to emulate a mag-stripe credit card swipe with your phone. A user pays at point-of-sale by placing his or her phone near the payment system’s magnetic stripe reader. This means consumers can pay with their phones at most U.S. merchants (gasoline pumps are an exception), and those merchants can continue using their current POS systems. This is …
