An app for managing your offline music & video library of MP3 and MP4 files, with support for editing some file metadata via long-press / right click.
A custom library folder can be set to support syncing via cloud services.
Music can be queued, and attached lyrics and art may be viewed in the player view.
Disclaimer: Edits are performed in-place. They should not lose any quality, but I can make no guarantee when it comes to the frameworks I make use of to enable metadata editing. Keep backups of your original files if you have an interest in preserving metadata or audio quality.