This is a simple MOD player. Using the FileExplorer framework to navigate your phone's file system. Using the SoundSystemDll with a plugged in ModPlayDll and SidPlayDll to play ProTracker MODs, S3Ms, XMs and PSIDs.
Check out UltraMod/UltraMP3 for a "real product"..
Start here for MODs: www.ModArchive.com
Check this for PSIDs: THE HIGH VOLTAGE SIDTUNE COLLECTION