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LingoDeer is a fantastic language-learning tool with a strong Asian- language focus (though it includes a few major European languages, too).  The app's courses are multilingual, so if you wish to learn Japanese as a German speaker, this is the app for you.  That said, LingoDeer is also quite challenging, as it features specific, high-level terminology and detailed grammatical explanations. Nonetheless, it is a superb resource, and the developer is constantly improving the app based on community feedback.

Many people fear not being unable to communicate with people from another country while traveling. Google Translate takes a bit of the edge off, quickly translating either written text or spoken words.  You can even use the app to do the speaking for you, and input text through your camera or handwriting. The app can translate 103 languages with a data connection and 52 when you're offline.  It can't handle Tamarian, but it's sure to be a handy tool here on Earth. Another option is Microsoft Translator(Opens in a new window), which offers 60 offline languages, travel phrasebooks, a real-time conversation mode, and actually translates Klingon.