Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Youtube-DJ - Mix YouTube songs together
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.
Pacemaker - Create and share mixtapes with friends
Codeship - Codeship is a fast and secure hosted Continuous Delivery platform that scales with your needs.
djay Pro for iPad - djay Pro provides a complete toolkit for performing DJs.