Re translations: we were using, what looks like, an outdated API. I have fixed the call and submitted corresponding pull request to Poor Maps ( https://github.com/otsaloma/poor-maps/pull/40 ). This seemed to fix routing instructions for OSM Scout Server Valhalla and Mapzen Turn-by-Turn. At least when I called Poor Maps with LANG=es_ES (or de_DE), I've got instructions in what appears to be Spanish (German).

Re separate option for specifying language: Maybe it would be great to have that option which would allow users to choose the second language. I would use it to get "Pirate routing version", but its surely not a high-priority task . So, would be nice to have as an option, but not essential with other aspects of navigation probably much more important.