In the app, content from the associated domain https://lobberich.de is offered via the location of the device (GPS) or accessed directly via QR codes. Another application is a picture puzzle that takes details from the cityscape out of context and thus alienates them. You have to find the locations.
Great importance was attached to data protection during development. Data with which the app works remains on the smartphone - the displayed content can also be called up via the Internet browser, so it is completely open. User data is not collected. The use of GPS and camera are limited to local display and QR code capture.