City Sightseeing Berlin

We just came back from having this bus tour and were trying to use this app. It does show the location of buses and the routes but it lacks the most basic functions, like: - no time table or schedule for buses. - no way to buy a ticket through the app, or to upgrade. You have to do it at bus stops by asking the people that work for the company. - overall the app was buggy, showing some popup when I would start it. - and also this service in general is quite confusing as to what ticket you need. We paid for one online but then it turned out that we needed to pay 8 more euros to take a green bus. This upselling is quite annoying.