I like Duolingo for language learning: https://www.duolingo.com/ I don't think its enough to actually learn language on its own, so it's best used mixed with a more formal method of language learning. It's fun and addictive enough that I actually keep using it, so that makes it good to me.
I’d highly recommend fluent forever instead. You’ll actually learn a language instead of thinking you are without making progress. It’s also much much faster.