Adding a language course is very easy (Remembering to have access you don't need to donate or like the app, when you do that you're just helping us keep the app active).
So let's now see how you can add a language.
When you log in just below, go to the "Learn new languages" section and "Choose a language" and click on "Add", choose the language you know best, and then choose the language you want to learn, click on "Save" and that's it, you can enter the modules and study them as you wish!