The app broke out of its mobile scheckles some time ago, with a Mac OS X version, for those that wanted to look a little more serious. So much so that 15 million of you have downloaded it to date. But, if you have a phone or a tablet (and a penchant for the old turntable setup, albeit virtual) then djay is an easy choice. If you see yourself playing in clubs and festivals, you'll likely be reaching for software like Serato, or Traktor. Algoriddim's popular mixing app djay is a lesson in mass appeal.