Android customization: how to set the volume level for each app with App Volume Control

While the new volume controls that Google has baked into Android 6.0 Marshmallow are certainly a major improvement over the confusing controls of Android Lollipop, most power users are still left wanting for more detailed sound volume management.

In this article, we’ll show you how to use App Volume Control, an app that allows for individual control over the sound volume coming from each app.
Why is this important? Well, for one, you could mute notifications when blasting music coming from your favorite streaming app, which is the example that we’re going to follow … – Source

Android customization: how to set the volume level for each app with App Volume Control