Really excited about this app but cant get it to work

I think this app will be super helpful and save money and time making my own flash cards - unfortunately I couldnt get it to work. I was prompted to login and after doing that successfully, I still was not able to download any of the vocab sets and kept getting a message to login. Additionally, I couldnt find a way to selected the language for the app to set it for German-English.

Cthreepio about Deutsch Vokabeltrainer