I found this "SoundAssistant" application in the play store by chance. It's the sound utility available on the galaxy series. It provides various convenience functions related to audio such as

Allow you to control the media volume by pressing the volume keys
Support individual application volume (You can control the volume of music and games differently)
50 steps of fine volume and support Floating Equalizer(EQ)
Create and activate personalize sound settings
Support mono audio and left/right balance
Touch the app volume icon in the floating dialog to play/pause and long click to enter the app.

If you are a Samsung Galaxy user, I hope this app will be very useful for you