We get questions periodically from people who want to manage ODK projects in a language other than English. Good news: @Matthew_White has just gone through the big task of pulling all of the strings out of ODK Central so that they can be translated!
We are working with partners who are translating it to Spanish and one of the ODK Collect translators to Czech has made excellent progress. We've also just gotten a request for French to be added (thanks, @bertrand_rukundo).
See the translation progress and join in at https://www.transifex.com/getodk/central/dashboard/! Please request languages that would be useful to you and check out our translation guide. Each string is provided with context for where it appears in Central. If you have further questions, you can either ask in in this thread or in Transifex by clicking on comments!