This app App could basically be renamed "Stalkr," but that doesn't stop it from being a personal favorite of mine. By turning on your location services, the app shows you people you've "crossed paths with," within one city-block. Then, like Tinder, you can "like" someone which opens up the option to chat. So next time you're on the subway and are too scared to actually approach a Ryan Gosling lookalike, download Happn and pray to the Sex Gods that he has the app, too. Bonus: Spotify teamed up with Happn to let you send songs to potential dates, so you can send a girl or guy a not-so-subtle hint by messaging them "Pony" by Ginuwine in lieu of a cheesy pickup line.