Google has added the mobile-friendly label to all languages and all localized versions of Google mobile search.
Google explained on Google+ that the label is “now available for all languages.”
Above is a picture of the mobile label on Google Japan. I’ve also documented several other languages, but you should soon be able to see it globally in any localized version of Google mobile search.
How can you ensure your site includes this mobile friendly label? Review the Google mobile guidelines and then use the Google mobile usability reports or the mobile friendly testing tool to ensure you are complaint. Do not forget, Google is experimenting with mobile ranking factors.