Hi 山内浩二! To monitor your position and alarms, running in the background is essential, but this is done very efficiently. Also, a new earphones setting has been released in version 4.2.0! You'll now hear the alarm through your BT device! If you’re willing, we’d love for you to reconsider your rating to help us make this app even better. 💚🌈🙏🏼🤗