A free program for Android, by nihonyamori.
What is Lisna?
Lisna is a music player that lets you organize your music into a folder tree. It supports MP3, OGG, MID, WAV, 3GP, AAC, M4A, MP4, FLAC, WMA, and other formats.
It lets you play your music in the background while you do other things. You can stop playing when a call comes in. It can also show you the level of the music in a visual representation.
How do I use Lisna?
First, make sure that you have your device connected to the internet. You need to be able to download the app and the music you want to listen to. You can also choose to set the audio output to either MP3 or AAC.