Square

In 2009, Dorsey co-founded Square, a mobile payment processing company. Square's initial product was a credit card reader that could be plugged into a laptop or mobile device, allowing merchants to process credit card transactions on the go.

The company quickly gained popularity, and Square expanded its product line to include a mobile point-of-sale system, Square Reader, which allowed merchants to process transactions on their mobile devices.

Under Dorsey's leadership, Square expanded its user base and introduced new features such as online invoicing and payment processing for online businesses.