One of the most requested languages on Duolingo is the beautiful language of Icelandic. It is a truly wonderful language that should certainly be more largely recognized. I'm calling out to everyone that speaks Icelandic to apply to the Incubator to add Icelandic for English speakers. If enough of us apply hopefully they'll let us work on it. If you know any good sites that teach Icelandic, leave a link in the comments. We can do this! Þakka þér fyrir alla. Gerum þetta. Ef við vinnum saman, getum við gert þetta með vellíðan.
There's so many European languages left to be added! I hope one day they make all of them!
I don't really know because I used this site only a little. But I think you can reach a level comparable to Duolingo. It has courses from beginner to high intermediate level.