To prevent missed when drunk.This app will play the vibration we get closer to the destination station.*** Notes ***This app has been using the location information network. I have measured is the distance "alternative" only. (Position error of 3G is usually located about 2km from 1km)In addition, in order to cancel the sleep on a regular basis, involves the consumption of the battery.Please use at your own risk and understand the above conditions.(As of April 2012, in the operation of the subway has not been able to confirm)Please use at your own risk and understand the above conditions.