MetroColour has been released for Windows Phone 7.5 Mango.  MetroColour turns your phone into instant disco.  Let a rainbow of colour metro tiles randomly appear and change on your screen.  Trial is fully functional advert supported.  No adverts when purchased.

MetroColour Windows Phone 7.

Also we would would like to note the ClueMan has been updated to 1.2 today and introduces a fully functional trial mode supported by adverts.  ClueMan for Windows Phone 7.