If you scroll down there's an executable download, description and screenshots. Kind of counter-intuitive I know (although there is at least one other app doing it http://github.com/rentzsch/clicktoflash), but there isn't really any other way to do it on github. It is Mac-only but I don't think that disqualifies it from being an app.

I have registered a domain name (http://pngsquash.com), but it currently just redirects to the github page because I thought that was adequate.