Smartphones: not necessary, but extremely convenient. My brain is too fried from lack of sleep to write a creative introduction to this post, so I'll just cut to the chase: Here are some handy travel apps that can make your travel life a little easier:
The app I use most frequently in Barcelona is called Citymapper and it's saved me on a number of occasions. It only has maps in select cities, but it continually adds more depending on demand. Right now you can use it in popular travel cities like Barcelona, London, Paris, Milan, Sao Paulo, Lisbon, NYC, Tokyo, Berlin, Amsterdam, etc.
Imagine arriving in the new city in a new country and not being able to speak the language and freaking the f@#$ out because you don't know how to get anywhere. DONTCHU FRET! Citymapper is here for you. It's not only a map app, it's a transit app that helps you with A to B trip planning in real time.
For example, say you're at your hostel and you need to get to the local camera shop to see if the price has gone down on that Canon AE-1 you've been eyeing. Open Citymapper, type in the address of your destination, and it will give you precise instructions on how to walk, bike, public transport, or cab there including the time it will take using each mode of transportation, the number of calories you'll burn, AND roughly how much it will cost. If you take the metro, it will even tell you the best section of the train to sit in:
You can also save your favorite places and view them all on the map so ya don't forget where they are (it's reallllly easy to forget where places are in the Gothic Quarter, El Born, and El Raval in Barcelona -- lots of alleyways and street names in Catalan):
In Barcelona, we have city bikes you can rent (well, only if you're a resident, but STILL) and Citymapper also gives you directions to the nearest place to pick one up or drop one off:
These examples are for Barcelona, but I have also used this app in NYC and Madrid and it's been a lifesaver when I'm lost. You will never use Apple/Google maps again!
I assumed that all people who travel knew about Kayak, but I've been proven wrong on several occasions. I think this app is the best way to organize your flight and hotel itineraries. You can also use it to purchase flights, find hotels, rent cars, track flights, get price alerts, pull up a phone number for an airline, and get information and maps of airports. Such a sweet tool that I use all the time.
My favorite feature is the trip organizer: when you sign up for a Kayak account and register your email address, every time you're sent a flight confirmation you can forward it to firstname.lastname@example.org and it will add your flight information to your trip. You can also send your rental car and hotel confirmations and it will add them to your trip. That way, you have everything you need in one place instead of 10 different emails. When I was still in the US traveling working for GradImages and had to fly places, rent cars, and stay in hotels and was always on a time crunch, it was a lifesaver. I also used it for my trip to New York in August.
I like the flight tracker as well, as it will inform you about delays and gate changes.
I don't generally use this app for purchasing flights unless I need a last minute emergency flight (which I did during a travel nightmare getting over here in June). I like Skyscanner better because it finds you the best deal.
Rail Planner can help you with your European rail journey. It's useful to for looking up timetables and you can view train schedules offline as well. I've never taken a train myself, but I've used this app to look up rail schedules for guests at the hostel. It was especially useful when I have the many guests that say, "Dang, I don't wanna leave yet, I want to hang out at this hostel FOREVERRR! But alas, I must make it to Seville by tomorrow. What time is the latest train I can take today?" BAM, consult Rail Planner.
If you have a Eurail or Interrail Pass, it's lists benefits for those as well.
The easiest way to get a cab. Choose your pick up and drop off location, cash or card, and you're solid. It will even give you a cost estimate. It functions almost exactly like Uber and Lyft in the U.S., but those don't exist here, so there's Hailo.
It's perfect when there's a language barrier because you don't need to speak with a cab company (I've recommended this app to numerous hostel guests who don't speak any Spanish). The only downside is that it only works in these countries: UK (London, Manchester, Leeds, Liverpool), Ireland, Spain (Barcelona and Madrid), and Singapore.
There are a ridiculous amount of travel apps available, but these are the ones I use most frequently. I will update this post as I find more that are useful.
And yes, I'm aware of Skyscanner and BlaBlaCar, but those deserve an entry of their own... Coming soon. =]