The add-on itself is OK. However, you can't switch UI language, it's defaulted to the browser language, and the translations are full of huge mistakes, and the overall language quality is awful which drives me away from using the whole thing altogether.

UPDATE: even though I contacted BW with this issue and even put many hours of work into providing good translations for these strings, nothing has changed after 6 months - still no option to choose UI language and the extension and mobile app is still using the same terrible and uncomprehensible text elements, simply ignoring the correct ones I entered. Sad.