Work on this as a Firefox OS app has stopped. See https://github.com/freddyb/squeezefox/issues/40 for more.
Squeezefox is a remote control for logitech squeezebox based devices. It allows you to see what's currently playing and comes with the usual play/pause/next/back buttons. You can also look at the current playlist and search for single tracks to either play them directly or add them to the play queue. Squeezefox also supports inspecting and playing your Favorites.
To use Squeezefox open the app and go to settings. Enter the IP address or the hostname of your server and a port (default is 9000). Squeezefox will try connecting to the server and give you an option of the available players. Select your player and start using squeezebox!
In a recent version of Firefox, open the App Manager (e.g. about:app-manager) and click on 'Add Packaged App'. Now select the squeezefox folder and the App Manager should recognize Squeezefox. If you have a device attached, click on connect and hit "Update" to install it on your device. If you have never used the app manager before, I recommend installing the "ADB Helper" extension for Firefox. It will make connecting and managing devices a bit easier.