Doulingo.com is a free language-learning app used by millions of people, but it has no tag here yet. So I wonder if questions about using Duolingo are OK here? Also, what would be the best place for them, according to the community here?
should they belong here?
should they asked on another SE site (which one)?
should a special site for Duolingo be produced through our Area51 (assuming it will get audience big enough - if advertised on Duolingo enough, this shouldn't be a problem)?
should they remain only on their forum and wiki and not to be discussed on SE?