Whats App – What’s App is a phone messenger service that lets you text internationally for free. Super easy.
Google Translate – Voice to text and back again, Google Translate is extremely useful when trying to communicate in those beginning (and middle) stages when language is a serious barrier.
Kindle – Oh dear, Kindle! Download books wherever, whenever. Make sure to get the one with the international download capability.
Rosetta Stone – Simplified language learning. For romance languages like Spanish and French, you would be surprised by how much you already know but did not realize you know. Rosetta Stone is pricey but easy. Conjugate those verbs!
Uber – Find a taxi quick. This tends to be set up more for the first world countries but it is a great service.