Jun 06.2018 - Version:
Streaming iTunes via AirPlay is great, but your keyboard's volume keys only let you control the system volume and not the volume in iTunes.
AirVolume lets you use your keyboard's volume keys to control the volume in iTunes whenever iTunes is playing via AirPlay.
AirVolume runs unobtrusively in the background. It is automatically enabled when AirPlay is enabled in iTunes and a track is playing.
When iTunes isn't playing via AirPlay, AirVolume is automatically disabled, and your volume keys adjust the system volume as normal.
Screenshots AirVolume for Mac
Video AirVolume for Mac