BarRemote (for Spotify)
Mac OS Music
Control Spotify on every Mac in your network from another Mac or from your iPhone.
BarRemote is a simple app that allows you to control the Spotify player from the menubar. You can control local playback or playback on other Macs in your network if they are also running the BarRemote app.
There's also a FREE companion iPhone app available in the App Store. The iPhone app will discover all the Macs in your network that are running the BarRemote app, and allow you to control any of them.
Discovery of machines is automatic, and you don't have worry about IP addresses or port numbers. The apps will find themselves and connect automatically.
Launch the app and you're instantly controlling Spotify on your local machine.
Playback controls can be shown or hidden from the menu bar, in the settings screen.
You can seek in the current playing track, shuffle, repeat and navigate the current playlist, control volume, and search the Spotify library to play albums and tracks.
More details at: http://codexbit.com/
TIPS FOR REMOTE CONTROL:
1. No more radio. In the office, have one machine that is playing Spotify. Using remote control, anyone can skip the annoying track, or turn down the volume if a call comes in.
2. For the curious. If everyone in the office is using headphones you can all peak at what each other is listening to. You obviosuly don't want everyone to be able to change your tracks. So just turn off the option that allows remote control of your machine. Now they can only see what you're playing.
Won't help you with those tracks you secretely enjoy and don't want anyone else to know though.
3. Move around. With your iPhone always around, control is always around.
Support for dark menubar in OS X Yosemite.