I am looking for an app similar to gpsmycity, where you need to follow a certain walking route (config in backend) and where you match pictures to a location.
Backend: configure start/end + stops with numbers to follow on a map. Add pictures linked to numbers.
Frontend: see your current location. See next stops marked with numbers. When on a number, you can drag and drop a picture to the number.
When all pictures correctly matched with numbers, end.