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 started Chinese, and it just seems so much of a mish-mash - it's like they just randomise testing and eventually you glean enough from the test questions to answer.
With French the closest I've come to learning, that I can point to, is from users answers to comments from other user. And the good and bad are mixed, there's no clarity.