Bingo Card Creator and Appointment Reminder. The latter is big enough he's started doing angel investing. Keep in mind, he runs both of them by himself and he no longer consults. I'm not saying he doesn't have an ulterior motive, but his motives are considerably more pure than 99% of the articles on hacker news.

Not that it matters. Who cares where the advice comes from if it works? And if it doesn't work, the purest motives in the world isn't going to make it work.