Whether it’s broken glass on the pavement or a smeared park bench: with a special app citizens can report sullied objects, things in need of repair or sources of danger directly to the municipal authorities round the clock. The technology not only supports the city during its work, but also promotes a sense of solidarity: everyone can do something for his or her neighbourhood. Pictures, short descriptions, and the coordinates of the location can be sent by app, enabling the municipal administration to remedy the situation quickly and in a targeted manner. The apps exist for many German cities.