Bulgarian (bg-BG) released. Tested mainly options window, as I could not find where to test the .properties bundle.
A number of entries there have serious gender translation problems: Bulgarian language uses gender specific adjectives and verb-forms, and in Bulgarian language most nouns have gender (table and synchronization are female, chair and host are male).
Overall however I am pleased with the view of the extension in Bulgarian locale.
I saw a minor visual glitch: the Settings tab->Import/Export/Save... buttons have their label on two rows, possibly due to my theme (Noia - I just love it). Probably a problem with a flex="1" somewhere. The images attached are actual tries to fix it by removing the flex space and setting flex="1" on the combo-boxes. I think spanning the combo-boxes looks better, but that is my opinion.