How good are your language skills? Probably not as good as the Pocketalk, which costs €332. It knows 74 languages, and all you have to do is talk to it, choose your language and it will repeat the necessary phrase back to you. You can even have a (slow, sort of disjointed, I imagine) conversation with someone in two completely different languages. It has got dual microphones, built-in speakers and will connect to wifi or mobile data to keep you connected no matter where you are. It's a little more expensive than your free Google app, but likewise using it won't kill your phone battery. So there's a trade-off.
Tech Tools: Translation device speaks language of convenience
Pocketalk handles 74 languages in two-way conversations
