Hi! At the moment it only supports MP3 files, nothing else. I have considered adding support for FLAC as well, but there are quite a few other features I would want to add first, that are higher priority for me. It would not be too hard to add support for the FLAC audio format, but FLAC files store their meta data (album name, artist etc) in a very different format than MP3s, so that is where the bulk of the work would be.