1.4 has been released on Amazon and Chrome, adding support for multiple logins. Now you can have more than one configuration saved and quickly switch between them without having to change credentials.
In addition (and technically, this was the unannounced 1.3),SubFire can be installed as an app via Firefox, for desktop and mobile. When running the app in the Firefox browser, look for the action button (next to refresh) in the upper right corner. You can click it to install the app directly onto your desktop or device.
Uninstall it by going through the normal application uninstall process:
OSX: just remove the .app file from your /Applications
Windows: uninstall the app through the control panel
Android: uninstall the app through Applications Manager
After I fix a few usability things (the 'zoom' that is broken for buttons in windows > 1441 wide, for example), I'll see about installing through the Firefox Marketplace.
One thing of note is that Firefox does not have the "currentTime" bugs that Chrome (>39) for Android has, which means that the music generally plays correctly. You may need to hit the 'Play' button to get things started even after loading a queue/album, but I'll see if I can fix that in the next few weeks.
I do not have a Firefox OS device at this time to see how it handles things.
The app is a hosted app (much like the Chrome app version used to be), so updates to the web version should be automatically seen on your device as they happen. I do not know how often (or if ever) the Android version will update its version number as the manifest changes.
1.4.1 has already superseded it on the web (and Firefox) and has been submitted to Amazon and Chrome. This adds the same action buttons to the folder browsing that are in the artist page: play-all, shuffle, top songs, and 'radio' mode (for server versions that have that support).