I added a Duolingo support. I know that Beeminder has its own, but it doesn’t suit me well. Here is why:
Duolingo has a feature called “Coach” that keeps track of your daily points. But it counts all the points from every language you are learning. On the other hand Beeminder’s native integration watches only one language per goal. Since I wanted to use Duolingo’s Coach as well as Beeminder, I decided to push the data my way instead of leaving it to Beeminder’s automation.