Yeah, click on the big red spot in the top left corner. Go to settings. It's the first drop-down box.
Eye -> Instellingen -> Taal -> Click on dropdown to open it. Scroll UP to English (silly Dutchies) -> Press Enter
You may also want to adjust the Scriptdefinitie field to en in a similar fashion. I left it on nl for the samples, will update it later once I've checked them out (and not a problem since I'm Dutch anyhow).
I think this tool fails a little because of the language dependency. Move the Turtle is more language independent, and Cargo Bot (links above) needs no language at all. Actually, I LOVE cargo bot myself, very challenging.