I saw this app up a few days ago in the app store - i noticed it in the top 25, and I remember thinking i would have even payed for this, it's exactly the kind of thing I've been looking for for my iPhone! Unfortunately, I haven't had a lot of luck with this program. I have close to 9,000 songs, just over 40GB of music, but the program always stops indexing around 7700 for some reason, and it doesn't work properly on the iPhone. The main issues with the iPhone app is that it only shows a portion of my library, and as I've discovered, of other libraries as well. Seemingly random songs are just missing, and I can only get a small portion of any library to show up. Also, the artist bios and lyrics don't scroll down, so you can only get the first page of them! There is also the album art issue and apparently password reset issues which have both been mentioned on their website cited earlier in this thread.
I had given up on this program and deleted it this morning, but then I saw this thread when I came to check for new updates, and after reading through the whole thing, I have decided to give it another chance. I wasn't aware of the context of the situation. I really hope you guys can get this together, I would love to see it working correctly!!!
Also, thanks a ton to everyone in this thread for sharing your usernames, I now have a huge list of pending invites, and several extensions of my library

You can add me if you'd like, my username is willydavidk, and as I mentioned before I have about 7700 being shared, a lot of alt rock, electronic, and punk, but overall a very varied library.
-David