Spotify has completely changed the way we listen to music. The ability to have free access (at least on our desktop) to almost any track imaginable is, simply, revolutionary. Pacemaker is the first DJ app that allows you to mess around with all those songs in that massive Spotify library. The app lets you get creative with tacks on Spotify or in your iTunes library and mix and loop to your ear’s delight. You can also pay to snag some effects to really open up the remixing possibilities and bring out your inner DJ.