The App „BahnDing“ allows users to establish contacts while beeing on a subway ride. Using the search and filter function one can look up potential App Partners, whether it's for a quick chit chat, a small flirt in between or an exciting adventure. GPS tracking allows for an automatic detection of frequently used subway routes and gets the location of users inside the subway wagons. This way it‘s easily possible to get an overview of potential interaction partners and their interests. The short-lived train rides are well-suited for casual interactions with other people. The project was developed during a semester at the University of Applied Science in Hamburg together with Nico Rößel, Anne Elias, and Mareike Graff.