Translation of vergeblich

If I wanted to integrate the above demo on our page, would we need to work with Vocabulix or do you have some other options? Could you send me some samples of other teachers, who integrated this demo?
We had time to walk around the waterfall but refrained from entering the little lake at the bottom. My fellow tourtakers were quiet nice and we spend a while just sitting in the grass near the water.
I put your lessons online. It gives you around 20 visitors daily at the moment. The lesson is shown only to specific users and only in the vocab builder section, as it is a trial. We see how it goes.