Ear Candy - Ear Candy is a sound level manager that nicely fades applications in and out based on their profile...
Sound Control - App-specific volume control
EarTrumpet - Volume Control for Windows
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Audio Sliders - Volume Control replacement that is five times smaller than its Windows counterpart.
SoundSource - The sound control that should be built into MacOS