Here a feature that likely has been proposed before -- permit JRemote to maintain (download) an offline database of a server's library. Note that I'm looking for offline playback, just offline perusal of the music library.
I've gone through the usual route of exporting the library to an Excel or Google spreadsheet and having that available, such that I can then check whether I have a given album or recording. (Classical music is usually more the problem.) The spreadsheet can be awkward to use at times, though (generally because it is both wide and tall). In contrast, I'm used to finding items I'm after fairly quick with JRemote.
Peeking at the "Main Library" information, my collection of about 1000 popular music CDs and far more classical music than that seems to be 26 MB (or is that MiB?) in size, seemingly easy to handle by a smartphone these days!
