Here is how we tested them: Language skills: I made an Odesk job for each language and got quite a few applications. THe first filering process consists of del

Here is how we tested them: Language skills: I made an Odesk job for each language and got quite a few applications. THe first filering process consists of deleting those who have below 4,5 stars, and thos who have't worked at Odesk for quite a while. Ideally 1000+ hours. The I sent a sample to the most promising candidates. These samples were all sent to professional translator, who picked their winners. Marketing skills: I asked every single translator how they would research keywords in their local language. Their answers will easily give you an overview of how reflected they are in this field. Plus, I only chose people who had done similar tasks before. Not everybody had done app localisations, but at least localisations for web marketing purposes. I can't be 100% sure that there are NO errors in the translations. But I can be 100% sure that this localisation will benefit my business, as it will increase downloads and revenue significantly. I know this from previous experience.