Weblate is close to 1.3 release (should happen on Friday if nothing urgent appears) and it's quite last chance for translators to catch up.
Weblate is of course translated using Weblate, but you can of course also translate Gettext po files directly and either upload them into Weblate or use Github issue tracker for that.
If you don't know Weblate yet, it is web based tool for translating with Git integration. You can also call it crowdsourcing platform if you wish :-).
I can do Polish if you like?