So sorry about that. I originally built this tool just for myself and ended up leaving a really messy localized bug in the old code that accidentally forced German on some users. Since people are actually using the extension now, I just dropped a massive v2.0 overhaul that completely fixes the language settings and rewrites the whole system. If you try it again, it should actually be in English (or whatever your browser language is, if it doesn't include that language, let me know) and work smoothly. Thanks for the feedback!