Square

Square, Inc. is a financial services, merchant services aggregator and mobile payment company based in San Francisco, California.
The company markets several software and hardware payments products, including Square Register and Square Reader, and has expanded into small business services such as Square Capital, a financing program, and Square Payroll.
The company was founded in 2009 by Jack Dorsey and Jim McKelvey and launched its first app and service in 2010. Square Register allows individuals and merchants in the United States, Canada, and Japan to accept offline debit and credit cards on their iOS or Android smartphone or tablet computer.
The application software ("app") supports manually entering the card details or swiping the card through the Square Reader, a small plastic device that plugs into the audio jack of a supported smartphone or tablet and reads the magnetic stripe. On the iPad version of the Square Register app, the interface resembles a traditional cash register.