1. WhatsApp (free)
By far my most used app. So long as you are outside of China, WhatsApp is most likely the most common messaging for Americans and everyone else.
2. Facebook Messenger (free)
Like everyone else these days, I hate using Facebook, but a huge part of my social network is there. Additionally, Facebook is the app that just about every person you meet also has.
Thankfully, Messenger is an aesthetically pleasing and pared-down messaging app that lets you tap into that network without having to be bombarded with your high-school ex’s political arguments.
3. Telegram (free)
Telegram has turned into my go-to for talking to sources in countries where the government might be watching what you say (*cough* China, Russia *cough*).
4. Google Maps (free)
I’m sure I’m not the first person to recommend using Google Maps to get around literally everywhere (except China), but the feature I find the most useful while traveling is the ability to download offline maps for places I’m in — that way, I can still navigate without blowing up my data bill.
5. Waze (free)
I can’t tell you how many traffic jams the social-navigation app Waze has gotten me out of. Turning every phone using the app into an information-generating node is just plain genius. I’ve found that it often has more accurate directions than Google in other countries.
6. My Currency Converter & Rates (free)
As I move from country to country, I am constantly using different currencies. It’s hard to keep track of what’s worth what. My Currency Converter & Rates is a simple offline exchange app that, while not so up-to-date that I would recommend forex traders use it, is just fine for the average traveler.