Sound Control - App-specific volume control
Google Home - Set up, manage, and control your Chromecast, Chromecast Audio and Google Home devices.
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Apple HomePod - The new home entertainment system by Apple
EarTrumpet - Volume Control for Windows
Sonos Move - Sonos has released their first truly portable speaker