Tangerine! lets you easily create playlists of upbeat music, or playlists for relaxing. It works by analyzing the BPM and the beat intensity of your music. Spend your time listening to music, not making playlists.

MP3 Trimmer lets you cut off portions of MP3 files, fast and easy, without re-encoding. Normally, you would need to convert the MP3 file to an editable audio format, like AIFF or Wave, edit the file, save it and then re-encode to MP3 again.