Bluetooth Volume Manager v3.0.3-rc0

This app allows Android to remember the volume of different Bluetooth devices.
Both music and call volume can be configured for each device. The timing and configuration for each Bluetooth device can be individually adjusted.
System Requirements:
Requirements: Android 5.0+

Home Page - https://play.google.com/store/apps/details?id=eu.darken.bluemusic&hl=en