Comment by graypegg

IMHO, if someone made something while following along with a tutorial, I do think they should be free to turn THAT software they made (with a guide) into a product. The presumption being that the tutorial isn't just handing you a product that you sell with no changes. (I do see there's access to the source code in the description.)

Skimming the video, and this site, I'm not noticing a ton of differences other than some minor styling changes. Maybe the author could mention any of the changes they've made? If they're significant, IMO, it's fine.