Packrat is a media collection manager application for Android. You can use it to add books, CDs, games, movies, etc. to your collection by scanning their barcodes and organizing them onto shelves. You can let Packrat organize your items into smart shelves, or manually stack items onto shelves of your own creation. You can also track items you don't have yet on a "wishlist" shelf.
Cuberok is a music player and collection manager with a lightweight interface. It supports music collections, CUE sheets, Shoutcast/icecast streams, a Last.FM and Libre.FM scrobbler, downloading images for albums and artists from Last.FM, information about artists from Last.FM, and lyrics from LyricWiki.org, automatic ratings for songs, and support for many playlists at one time.