Acorn grew out of upgrades to another app of mine, FlySketch, designed for screen capture and sketching. Customers asked for new features, I started adding brushes and layers and multiple windows, and all of a sudden I had a full-blown image editor. But Acorn still serves different needs than professional-level editors. Acorn is powerful, but nimble and approachable. It also has excellent documentation that we’ve worked hard on for years.