I have no clue. But, based on the theory that I really just don't want to get sued, even if I happen to be right, it seems important that neither does the author:

> permits you to use TypeIt in any [...] personal project

That's trying to establish some requirement to be non-commercial, which the GPL doesn't do. In fact the author here should know this better than most people, considering they are trying to sell something that's also GPL-licensed.

So if you get a good lawyer to give an all clear to use this in your Uber-for-Platypus-Stylists venture, they will get just as mad as if you don't.