Chrome Extension Translation

We have a Google Chrome extension that needs translation into multiple languages. Currently we have used Google Translate to write our copy in languages other the US-English and VI-Vietnamese. We want someone that has experience translating and can make sure the translated text for our extensions makes sense and is what people will be searching for. SEO help for languages related to our keywords would be a bonus. It is possible that we will need more than one freelancer. That is fine we can hire several. In your proposal please let us know what languages you can translate. Our target languages and what we have so far. US- English - Completed PL-Polish - Google Translated