When I set up my living room Media Center, I decided to also install the Logitech Media Server to stream music stored on my external hard drive to other computers, Logitech Smart Radios and the Media Center itself. There are already apps for iOS and Android that allow you to control the devices connected to your Logitech Media Server, but I couldn't find any apps for Mac OS or Windows. The built-in web interface is a good start but it looks very old and not minimalistic enough, so I wrote my own app, LMS Remote. LMS Remote allows you to control your connected devices and shows you the currently playing song together with nice cover art and fanart backgrounds. You can use it as a controller, as your main music app or as a status display on your second screen or TV. The layout adapts to the window's size. Using the Quick Search field, you can start an Album, Track, Artist or Favorite by typing in the first few letters.
If you have ideas or questions regarding this app, just leave them in the comments below or in the official thread on the Slimdevices Forum.