As of BPBible 0.4, BPBible has supported translation of the user interface.
If you would like to help out, please check whether the language you would like to do has already been done. If it has, please act as a proofreader and check the translation. If not, please read the instructions on how to translate BPBible, and make a translation! When you've finished, send the ZIP archive you've made to firstname.lastname@example.org, and I'll put it up here.
Languages we currently have:
Languages we would really like done: