G. D. Penman ghostwrites non-fiction on a wide variety of subjects. Based on the sheer volume of books that he has ghostwritten there is a reasonable chance that there is one of them in your home right now. They are like rats that way. At the last count he had written 50, but of course he can't tell you what any of them are.
He has worked as a literary critic for many years in a variety of venues, but you can find his most recent work online at Bookwitty.
As an avid fan of the hobby, G. D. Penman has also produced a considerable amount of content for tabletop role-playing games. Working with companies like Shades of Vengeance, Squidtusk and Gloomy Shrooms to produce scenarios, background material and even several full games.
If you would like to commission some work you can contact him via email: gdpenman (at) gmail.com