Youtube-DJ - Mix YouTube songs together
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Pacemaker - Create and share mixtapes with friends
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
djay Pro for iPad - djay Pro provides a complete toolkit for performing DJs.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.