This is a SUPPLEMENT to Serato Dj on the computer. It is not for replacing the program and is not a stand alone app. People giving negative reviews dont understand that and are the type of people that only drink protein shakes and get upset when they find out they are vitamin deficient. If you have one of the newer controllers you may not need this app. Check the videos and see if its an app that adds features you need. The price is the only thing I wasnt too happy about... But very glad with the purchase.