Duolingo for English/ESL?
Are you considering doing this? English is my first language, but I think a lot of people would benefit from an English Duolingo. You could take a more picture-based approach instead of translating every sentence into every language...
I know this post is old, but I agree, I think it would be great! Especially with the new Duolingo Classroom. I'd like to use it for my ESL class but many of them speak non-supported languages.