Suggestion for improvement: Let us select ALL of our courses from the language drop down menu.
It seems to be a relatively popular option to do reverse trees or laddering trees when learning a language. (That is, if, say, I am learning German and French from English, I also do English from German, English from French, German from French and French from German. I think this is a great way to reinforce your languages. However, changing between these options is a bit annoying, you have to fo to the language menu, go to "add course", go to a different page where I choose my origin language, then choose the language I want to learn...
I think a lot of people would appreciate if we could just directly switch between any of our courses from the language drop-down menu, regardless of our language of origin.
Duolingo seems so unenthusiastic to implement such a feature they actually made it substantially more difficult to switch among courses from different base languages in the website rewrite.