I work ~4 hours a week making aircraft add-ons for X-Plane, releasing one product every 3 months, net profit ~$5k a month total.

It's fairly simple: 1) Commission Russian 3D artist to make model of aircraft -$1000 2) Commission Audio Engineer to do sound - $500 3) Tweak model to work well with simulator + animation - 12 hours 4) Paint model in Substance - 12 hours 5) Set up flight model in X-Plane's "Plane Maker" - 8 hours 6) Coding - 12 hours 7) Misc loose ends & testing - 12 hours

I don't talk about it because I don't want too much competition figuring out what an easy way this is to make money.