duolingo.com
Learn a language in a few minutes a day, like a game.
Strengths
- Fun, game-like lessons of a few minutes a day
- Dozens of languages, plus math and music
- Streaks and leagues that keep you motivated
Limitations
- Free energy system limits practice to about 15-20 minutes a day
- Not enough on its own to become fluent
- Lots of ads and nudges toward Super
