I've been contacted recently about a VC firm offering $350k+ for a frontend developer to own the frontend web app. I had to turn it down due to lack of flexible hours, but it otherwise intrigued me.

I also have been told by a friend that his brother ran a company that was acquired by Google for $100m, and suspects that his brother makes several million $ a year from Google (he wasn't ever told how much) - that is probably more of an outlier though.