I use my iPad to play music through my speakers. Is there an app that i can control the volume through my MacBook Pro or iPhone?

I mainly use the apps such as Spotify and also the music storage on my iPad to play music through my speakers and as I'm working in a different part of the room, i would like to be able to control the volume from my mac or iPhone. Is there an app to control this? I know i can sync my iPhone and iPad to change the track and start/pause music on spottily but not sure about the volume control.

Thanks,

Will