Since we are still getting set up, if you would like to join the translator team, join our translation mailing list.
Currently, our only supported languages are English and German.
Prior to each new release, we will mail out an easy-to-read copy of JKaiUI's language file. Further detailed instructions will be provided per email. The language file has a section for you to enter your name so you can be credited on the program's About page.
If you have any questions, feel free to ask in our Help Wanted thread.