Microfi Nitrogen is a native Windows Mobile application (unmanaged code) that allows you to play MP3/OGG/AAC/MP4/M4A/3GP/WAV/WMA songs stored on your Pocket PC device.
It features a file browser, full skin support, smart shuffle and repeat modes, a 10-band equalizer with preset support (8 included presets), built-in sleep mode, a blank screen command to prevent energy waste while playing music and many more new features. Nitrogen uses the MAD/OVD decoders, which are opensource. As the official releases of MAD for Pocket PC seem to be discontinued, Nitrogen uses the libraries from an opensource player (GSPlayer).
Nitrogen was build due to the lack of finger-friendly players for Pocket PC (you have to use stylus even for simple tasks). It features large buttons and you can browse among your playlist by drawing circles on the screen (using skins which support wheel component). In future releases the program will be expected to have other extensions support and more features, but such things are still being tested to ensure stability and efficiency.