Were you using the Snow Leopard version until now? If so, you have to download the version for OS X 10.7 and higher, because GateKeeper prevents the Snow Leopard version to work on Mavericks.
http://www.macupdate.com/app/mac/40674/coollector-movie-databaseI don't have installed Mavericks myself, but 1 user has reported that everything worked fine with it, and from my server logs, I can tell that many users are downloading pictures from Coollector running on Mavericks.