Sound Control - App-specific volume control
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
SoundSource - The sound control that should be built into MacOS
Power mixer - Power Mixer is a complete Windows volume control replacement.
3RVX - 3RVX is a skinnable volume display and controller.
Audio Sliders - Volume Control replacement that is five times smaller than its Windows counterpart.