Jon Swartz for USA Today:

Today, the company co-founded by Twitter inventor Jack Dorsey unwrapped Square Register, a free Apple iPad app designed to modernize point-of-sale devices for small merchants. “I truly believe POS, as you know it today, is dead,” says Megan Quinn, director of products at Square. “This will bring Square to an entirely new, small-market audience (bricks-and-mortar stores).”

Using Square Register, a merchant can set up a point of sale system using an iPad and Square’s credit card reader. Existing point of sale systems can cost retailers quite a bit to obtain and maintain, while Square Register is free to download. The service charges merchants a fee per transaction in order to make its money.