James Thomson

James Thomson is a Scottish independent developer based in Glasgow who has been making Mac and iPhone software through his company TLA Systems since 1992. He is best known for PCalc, a long-running scientific calculator for Mac, iPhone, iPad and Apple Watch, and for DragThing, the classic Mac dock utility.

Thomson started PCalc while studying computing science at the University of Glasgow and has kept refining it for more than three decades. He also worked at Apple on the Finder and the Dock during the development of Mac OS X before returning to full-time indie work. TLA Systems also sells Dice by PCalc, a dice-rolling app, while DragThing has been retired.

He is a familiar figure in the Apple indie community, appearing on podcasts such as AppStories to talk about sustaining a single app over decades.