iMashup is a mixing app for iOS made by Mixed In Key. I worked in this project as a lead designer. Within three days of its release Apple featured iMashup on the front page of App Store in every spanish speaking country, and in less than a week it was 6th most popular app in the US music section.
You can get the app from here. https://itunes.apple.com/us/app/imashup/id503804151?mt=8