Volume Mixer : Per Application Volume Control

Per application volume control for your mac.
Now works with El Capitan.

By default, the app can control your mac's master volume and iTunes. However, with a free optional add-on, the app will let you control volumes of all running apps individually (including any games, browsers, VOIP clients and music players you have on your computer).

Supports output devices other than built-in speakers, so you can route audio to your Bluetooth speakers, USB headsets or even HDMI televisions while still using Volume Mixer.

To download the free add-on, please visit our website.
http://www.volumemixer-app.com/