put up a form to ask for the name of the station, and get the browser to share the gps location. also ask for which lines stop here and where they are going. submit all that to openstreetmap.

then do a search on the station name and gps location and display some useful information.

for the scavenger hunt, save the station codes in local storage in the browser, so that visitors can track their progress but you don't track visitor movements. only upload highscores to the server.

also display a random family friendly joke to encourage scanning.

experiment, see if you can find something that makes this go viral...

let people submit photos of the station...

let them report on bus delays...