I was surprised this article doesn't mention DrawIt [1], Bohemian Coding's first (?) drawing app designed for UI elements and icons, which would seem rather familiar to any Sketch user today. It combined vector and pixel graphics, and allowed you to compose any number of effects like blurs, borders, shadows, bevels etc in a non-destructive stack.

Sketch was launched a few years later [2], and the way I remember it, it first focused more on vector art illustration on an infinite canvas. It was only later that DrawIt was retired while Sketch took over a lot of the UI/icon tools.

I always felt like the Sketch we have today is much more like the first version of DrawIt than the first version of Sketch.

1: https://web.archive.org/web/20090609142331/http://www.bohemi...

2: https://web.archive.org/web/20110225224308/http://www.bohemi...