This seems great, bit different than traditional audio tours. Especially for those who want to quickly explore the city, but don't know any locals, who could guide them.

In Paris, we went for a traditional guided tour ("Paris with Chris / City Free Tour"), which was great, but you have to adjust to their schedule and walking pace.

I don't see myself using this app together with my friends (as in part of the video), because we couldn't discuss the sights at the same time. But when I'm travelling alone, this seems like a fun option.