The objective-c app is able to analyse the motion of the bike by an accelometer. The threshold value for a pothole can be adjusted with a slider to define the individual complain level. When a pothole is detected, the app sends the information to a server, which identifies the address throughout reverse geolocation and records everything into a database. Meanwhile, the app sends an audio signal to the spray device, which consists of an arduino pro mini, an own circut, a solenoid and a spray can.