tomas is from Mapfactor. And I think he is right. If OSM maps do not have (English or other) tranlation tags, Mapfactor would not be able to provide them (but only with substantial effort).
You could go to OSM, register as a contributor and provide tags with foreign languages. A couple of weeks later you will have them in Mapfactor maps. If you cannot read Greek charactors, you would have to ask somebody else to edit OSM data, you want to have.
Coming back from Holidays on Crete I can tell you how it works. Let's take a Village called "Panagia" but in Database it is written only in greek characters. Searching for it using latin characters Navigator free showed several Panagia's even in greek and latin Characters. I also found out, that most Villages exept those in deep nowhere are signed with greek and english Name on signposts at their entrance or road-exits directing to them.