The guide was useful in prompting us to see the best bits of the old town. But the location technology was unreliable and often started a description before we had reached a place, or described a different plaza from the one we were standing in; it was then difficult to stop it and the app sometimes hung when we tried to do so. The verbal direction instructions were not clear and the Google Maps links to the next landmark all sent us in the wrong direction - we had to check which plaza was next and input it manually. The descriptions were quite helpful and interesting, but we got as good or better information from the free suggested walking route leaflet that we were given at the tourist office.