YaPLayer
YaPlayer is an mp3 player editor. With YaPlayer you can build custom interfaces placing controls like buttons, labels etc. and assigning actions and properties to them using WYSIWYG editor. It also allows the user to animate controls' size and position setting keyframes and doing linear interpolation between them. The player's interface is saved into an XML file. To directly run the player just drag and drop the xml file on the YaPlayer executable or pass the xml filename as command line parameter.