Even though it is a great project/product, note that it does not have realtime data in Berlin/Brandenburg. It interpolates the position based on schedule data [1].
Thank you for posting this: This also has the Danish real time data presented in a much cleaner way than the various web services of our local operators.
[1] I assume based on https://daten.berlin.de/datensaetze/vbb-fahrplandaten-gtfs