If I am looking to learn another language, Duolingo gamifies language learning with bite-sized lessons and a friendly interface. Starting with simple vocabulary and building from there, Duolingo is your guide to learning a new language or brushing up on one I already know. The more I use the app, the more I unlock and—with practice—the more I learn. This free app currently supports Danish, Dutch, French, German, Irish, Italian, Portuguese, Spanish, and Swedish. Or more practical choices, like Esperanto and Klingon.