Jack Dorsey is an American computer programmer and Internet entrepreneur who is co-founder and CEO of Twitter, and founder and CEO of Square, a mobile payments company.
As a kid Dorsey was captivated by maps and the cities they described. As a teen he became interested in the dispatch services used by taxi services and other transit systems. At 16 Dorsey tried to start his own bicycle courier service, in part to have an excuse to write code to run the business–until he found little demand for bike messengers in St. Louis.
Williams, Stone and Noah Glass co-founded Obvious Corporation, which then spun off Twitter, Inc., with Dorsey as the Chief Executive Officer (CEO). As chief executive officer, Dorsey saw the startup through two rounds of funding by the venture capitalists who backed the company. He reportedly lost his position for leaving work early to enjoy other pursuits, such as yoga and fashion design.
Dorsey, along with co-founder Jim McKelvey, developed a small business platform to accept debit and credit card payments on a mobile device called Square, released in May 2010. The small, square-shaped device attaches to iPhone, iPad, iPod Touch, or Android devices via the headphone jack, and as a mini card reader, allows a person to swipe their card, choose an amount to transfer to the recipient and then sign their name for confirmation. Square is also a system for sending paperless receipts via text message or email, and is available as a free app for iOS and Android OS.