I remember in my teens using free trainers from Cheat Happens and trying to figure out how to use Cheat Engine to coast through some games (most of the time when I cared more about the story than the gameplay itself), also around last week I even saw a video on YouTube where the sponsor was a company that provided trainers as a service for a large catalogue of games, all in a neatly packaged client.

It's nice to get a look behind the scenes at how it's done.