Duolingo is a website where you can take courses in several languages. The learning method are quick and varied exercises, grouped in lessons.
Ayni is a platform on which you practice languages with native speakers.
Post in the language you're learning, and get advice from native speakers.
Words Keeper is a simple web app for foreign language learners. It lets you build your own vocabulary, keep everything in one place and group by category, create learning groups,...
Tests your listening comprehension with quizzes. Plays recordings of sentences or texts, which you then write down.
Know any negative aspects of this option?