Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Ring4 - Manage business phone line as easily as you manage emails, in the cloud. Ring4 provide you with a business line and video conferencing solution.
Sound Control - App-specific volume control
SpotMenu - Spotify and iTunes in your macOS menu bar
Power mixer - Power Mixer is a complete Windows volume control replacement.
OpenPhone - Simplest way to own a business phone number