I have several suggestions:
1) Ability to use self-hosted files, be it images or sounds. I've seen people asking for adding own sounds to jukebox via upload, but it really makes sense to use, say, Dropbox to host own campaign resources. It takes load off your storage servers.
So please allow providing an URL to a resource instead of uploading. Possibly with strict requirements on content formats, but it's better than nothing.
2) Please add support for some format of vector assets, e.g. SVG. This will both save space and will look better resized.
3) Not all sounds in the jukebox are meant to be looping. Music/ambient is okay, but SFX should play once. Please make a per-sound option to loop or not, or a button to play once.
What would also be cool is to have a fade-in / fade-out effect on SFX/music.
Sorry if some / all of the above was already suggested.
