Its true that it doesn't work on OSX 10.8 either. I think people are making assumption that Mavericks broke MTP on OSX. I still haven't upgraded to Mavericks and Jolla don't show up for me either. I guess they had somekind of syncing solution ready that doesn't work on Mavericks, but I don't understand why plugging Jolla to my hackintosh won't work, if they had solution pre-Mavericks/OSX 10.9.