RjDj (Reality Jockey Ltd.) was a startup founded in late 2008 by last.fm co-founder Michael Breidenbruecker. The company was based in London and was run by a small team of four employees.Its mission was to create sonic experiences specifically designed for the latest generation of personal music players. RjDj produced and distributed a network of mobile applications and sold additional musical content within this network. RjDj closed its website and removed its apps from circulation in 2013.