Duolingo English is a free, game-like English learning system for Web and mobile devices that has taken off like crazy in the last couple of years to become the most downloaded education app in the world.
Duolingo for learning English is free and fun - and an independent study shows that 34 hours of Duolingo practice is equivalent to one semester of university-level English.
Duolingo's free English course is great for beginners and intermediate learners. It teaches you English from step one and plays like a video game - including the addictive part! The learning system is visually stunning with cartoonish graphics and photos to illustrate vocabulary and concepts and help you memorize them.
Most importanly, perhaps, is that it is quite fun and keeps you coming back for more learning. Thus, there is no lack of motivation to learn that new language.
Duolingo offers free apps for learning English on iPhone, iPad, iPod Touch, Android and Windows devices.
Duolingo makes it possible to get certified proof of your English skills for work and studies.