Hello there! I found this guy on itchio and he seems suspicious to me. Maybe he created all these, but it seems to me that it is more possible that he just went around the web and collected tutorials or capx templates from other people that were giving it for free to help others, and he is just selling them to profit.
hafizduddin.itch.io/source-code-for-construct-2-120-capx
I think that when I was looking for free templates to create my games with, I saw a few of these, like the cat mario one.