This application make mute the music volume when you unplug a headset(earphone/bluetooth A2DP device) from a phone.
it unmute the music volume automatically when you plug a headset.

Note for Android 6.0 or later.
Mute API was deprecated since Android 6.0.
This app fix volume to zero instead of Mute API.

Test:
Android 6.0: Xperia Z3+(Z4)