The first major program I made was for what, so I can download many albums at once after my hard-drive failed. What had a feature known as "Collector" which gave you a zip of an artist's discography. With my program, you could dump that zip right in and it would send it to utorrent downloading in a structured directory (per user settings). I would have never taken it as far as I did (GUI from command line tool) if it weren't for the community loving it and giving me feedback to make it better & better. I called it "collector's secret lover".[1]
Another one I did was for nice looking release info of torrents called generically "description generator". It gave users an easy way to grab all relevant info (from discogs) for an album upload so they can copy and paste [2]
This is a sad day, what.cd was much more than a place to just download music.