Square is a revolutionary service that enables anyone to accept credit cards anywhere. Square offers an easy to use, free credit card reader that plugs into a phone or iPad. It’s simple to sign up. There is no extra equipment, complicated contracts, monthly fees or merchant account required.

Co-founded by Jim McKelvey and Jack Dorsey in 2009, the company is headquartered in San Francisco with additional offices in Saint Louis and New York City.

More information: Square.