From maps to money to making reservations, these were some of the smart phone apps we found most valuable during our year-long journey around the world: 

• Although the first item is not technically an app, for us, it was an invaluable tool. Before embarking on our world tour, we switched our wireless carrier to Google’s Project Fi, which (for us) turned out to be a huge money saver. The service works by pinging off three major providers – U.S. Cellular, Sprint, and T-Mobile – and provided reasonable coverage for most countries we visited. The plan was about equivalent to what we payed for domestic service (for one phone) in the U.S., costing $20/month for unlimited international texts plus $10 per 1 GB of data usage (voice service overseas is free over Wi-Fi but cost varies by country over the cellular network). The trick to keeping the service’s cost down is by limiting your data use. For us, this was pretty easy to do – if we wanted to do anything major, like uploading photos or videos, we connected to free WiFi provided by our guesthouses, local libraries (if convenient), or whatever cafe we happened to stumble into.
• Before traveling to a new area (either a city, region, or entire country), use the Google Maps “offline areas” feature to download the maps offline. Having the maps saved offline is really useful when you have no cell or WiFi available. We’d then delete region-specific maps upon departing each country, as the files are quite large and take up a bunch of space on the smartphone.
• Maps.me is a pretty decent app offering free maps, and we found it to be quite popular amongst fellow travelers. While the maps aren’t quite as comprehensive as Google Maps, we found it particularly handy in countries that don’t allow Google Maps to be downloaded offline (e.g. some countries in Southeast Asia).
• VPN app (e.g. Express VPN) – provides an extra layer of privacy protection when connecting to public WiFi networks (important for banking or other transactions involving sensitive information)
• AirBnB – great for finding inexpensive lodging (we had fabulous experiences just about everywhere using AirBnB)
• Trip Advisor – restaurant and accommodations reviews
• Hailo – fixed-rate taxi bookings in London & Ireland (as well as a few other locations worldwide). This is just one example of an app for calling a cab (many countries/cities have their own app). The fixed rates are comparable to a metered taxi, but such an app allows you to get the price ahead of time, which can give some insight as to whether someone’s trying to take advantage of you with an inflated rate (common in a number of cities). Additionally, it allows you to track the vehicle, so you know the driver’s ETA.
• Uber – transportation (private hire); typically less expensive than taxi service, and also provides the aforementioned benefits of avoiding price-gouging and tracking the driver’s ETA.
• Flix Bus – cheap bus service throughout Europe (often a fraction of the price of a train ticket), and just a really well-designed app, providing bus routes, stops, maps, ticket info, and a hassle-free booking service.
• GoEuro – booking app for trains, buses, and flights across Europe
• Trainline EU – rail bookings across Europe
• Parking app (e.g. Ring Go, PayByPhone) – allows payment by card at metered parking spaces in numerous cities (look up specific city apps before arriving).
• WhatsApp – texting and chat
• The Weather Channel App – weather reporting (we found 1Weather to be significantly less accurate in their forecasts)
• World clock – allows you to always know what time it is back home, ensuring you don’t miscalculate the time difference and accidentally ring your loved ones at 3 a.m.