A free app for Android, by pelya.

This is a very useful app for tracking your music, even if you don’t have a fast and stable Internet connection. You can use it as a standalone player. It supports many formats and even plays some of the most common audio formats, such as mp3, wav, wma, m4a, ogg, and flac. 

With the music loaded, you can start editing it right away. The editing options are pretty much the same as in FastTracker, but there are a few differences. First, this app has a full-screen mode available. Second, the default setting for the volume is different from FastTracker. You can now set the volume to a value between 0% and 100%. You can also set the volume as a percentage of the normal volume, instead of a fixed value.