I don't think it's a joke. I think it's made to assist scalpers in buying limited-supply items from web sites and circumventing order limits -- that'd explain some of the weirder features mentioned on the home page, like per-tab proxies and "queue statistics".

I am disappointed to discover that this is a thing, but also completely unsurprised to find that someone else is trying to make money off of it. Where there's a niche, there's a way.