There should really be more courses for German speakers. I noticed that German only has 3 courses; English, French, and Spanish. I don't think a Dutch for German course would be too hard to make, as they are very similar. I hope that in 2018, the incubator adds Polish for German and Dutch for German.
Swahili, Norwegian, Hebrew, Swedish, and Danish don't have any courses, not even ones that teach English. Another hope for 2018 is that these languages eventually get a course for themselves.
Finally, I hope that every language on Duolingo soon has an English course, a Spanish course, and a French course soon enough. It will take a while, but it will be rewarding.