Sumdog math games are produced by Sumdog Ltd, a Scottish-based company led by founder, owner and CEO Andrew Hall, as of 2015. Since Sumdog is not a publicly traded company, more specific information on Sumdog is not available, but Hall may be credited with creating or inventing Sumdog's math games.
Hall's role regarding the invention may be compared to how Steve Jobs is credited with the iPhone, or Bill Gates is credited with Windows. Sumdog was founded in 1993 by Hall, and formally incorporated in 1996. Hall has an education in electronics, and previously worked as a designer for Texas Instruments and ST Microelectronics before starting his company, Sumdog Ltd.