You may think you need Wi-Fi right now -- with your limited data plan and your Netflix-watching obsession -- but you don't. You don't truly need Wi-Fi until you're stuck in at a bus stop in west Tokyo, with no data plan and no idea how you're going to get in touch with your brother who's supposed to pick you up...sometime this evening.
It's one thing to find free Wi-Fi when you have access (even if it's limited access that you're paying for) to the Internet. Here's how to find Wi-Fi when you're traveling abroad.
Find an Apple Store (or a Starbucks, or a McDonald's)
Some places always have free Wi-Fi, no matter where you are in the world. My go-to spot for free Wi-Fi is the Apple Store -- most major cities have at least one, where you'll find an open network (you don't even have to agree to a ToS), air conditioning and no pressure to buy anything.
If there's no Apple Store in your area, Starbucks and McDonald's also offer free Wi-Fi in almost all international locations.
Not all free Wi-Fi is completely free -- many restaurants, coffee shops and cafés offer "free" Wi-Fi to patrons, and will usually require that you purchase something before they give up the password to their network. For truly free Wi-Fi, look for public transportation hubs (airports, train stations and bus stations), places where tourists are likely to be (museums and other attractions), and community spaces (libraries, parks and public squares). Malls and large department stores often have free Wi-Fi, as do convenience stores, bookstores and hotel lobbies.
Use an app
My main issue with Wi-Fi finding apps is that they usually require an Internet connection of some kind. So if you're traveling abroad and you don't have a cellular data connection, you'll need to first find Wi-Fi in order to find more Wi-Fi, which is not very convenient. But I have found a couple of apps that work well (and offline): Instabridge (free, Android and iOS) is a Wi-Fi password-sharing community that auto-connects to nearby networks. It has a database of 3 million hotspots, which sounds like a lot but really isn't when you go abroad. WeFi Pro (free, Android), on the other hand, has over 200 million hotspots, and therefore has a better international presence.
If you're inside a restaurant, café, or random business that doesn't advertise free Wi-Fi, turn on your phone's Wi-Fi and pull up a list of nearby networks. Chances are, you'll see a locked network named after the business you're patronizing -- try asking your server or a sales associate for the password. Many places are happy to share their Wi-Fi with you free of charge, especially if you pull the tourist card.