whats this karma reddit decay download thing in the downloads section?

it says gamechief made it, what is it?

I just downloaded it and all its showing me is a ton of code

karma decay is reverse image search for Reddit, so you can check re-posts.

Charles made a thread for it.

It's a Greasemonkey (Firefox)/Tampermonkey (Chrome) extension. It adds a link to karmadecay on reddit for image submissions. Karmadecay is a reverse image search for reddit that tells if an image ahs already been submitted in the past.