A city walk with a local guide is a great experience, but it is also possible to do a city walk on your own using the Motes web app. The app is easy to use and you can choose from several trips, e.g. In H.C. Andersen's Footsteps and a treasure hunt for families.
All you have to do is click on the link, choose the language and the tour you are interested in, then Motes will do the rest. Remember that Bluetooth must be turned on.