Until AM is described as 'online DJ tool featuring virtual turntables with scratching and live effects' and is an website in the Audio & Music category. There are five alternatives to Until AM, not only websites but also apps for a variety of platforms, including Mac, Windows, Linux, Android and iPhone. The best alternative is VirtualDJ, which is free. Other great sites and apps similar to Until AM are Djay (Paid), YOU.DJ (Free), Serato Scratch Live (Paid) and itDj (Paid).
itDj is a Commercial Dj software (with limited free trial) - (the trial download isn't apparent, on the website, it can be downloaded here: http://www.itdj.com/download) itDj lets you beat-match, scratch and add effects to your music in iTunes and on your Mac.