geofencing application for android use firebase database and Geofire Library including service. The original tutorial link and all credits goes to: https://www.youtube.com/watch?v=Rwz-F4YOMBM&lc=z23ver0rkmjuxrd1zacdp432mpjzhqh2vpqugdk2iklw03c010c.1525394303781475 and Farhad2015/Geofence-GeoFire
Repository created for answering this SO question https://stackoverflow.com/questions/50306777/how-to-add-background-service-in-geofence-android/50485798#50485798