EarTrumpet - Volume Control for Windows
Apple HomePod - The new home entertainment system by Apple
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Google Home - Set up, manage, and control your Chromecast, Chromecast Audio and Google Home devices.
Sound Control - App-specific volume control
BOSEbuild Speaker Cube - Build-it-yourself Bluetooth speaker for curious kids