is it possible "public transport routing" with OSM? Using osmDroid, Graphhopper or other Libs.
I build a navigation app and i wanna navigat with car, bike, foot and public transport.
This depends on the routing engine you want to use. GraphHopper doesn't support public transport routing. But according to the list of OSM online routers public transportation is supported by OpenTripPlanner, TripGo and Mapzen Turn-by-Turn.