Until now, Pacemaker only let you create basic mixes from Spotify tracks (you need a premium subscription), or music from your iPhone library. You could control how and when the songs overlapped, save your mix, and share the result. The update bakes in a bunch of social features so you can follow friends, see their mixes, and even edit them -- so if you don't like that dodgy Diplo mix in the middle, swap it out for some Jack Ü. These new, edited mixes (and of course your own), can then be shared back to Pacemaker for a never-ending stream of modern day mixtapes.

The new feed takes one of Soundcloud's best features -- the ability to follow or discover up and coming artists -- making Pacemaker interesting to those that just want to enjoy music, even if they're shy of stepping up to the virtual DJ booth themselves. Naturally you can comment, like and see what's trending as per anything social these days. Of course, the Spotify integration also means all the performers involved get a digital penny for their troubles, too.

For those that do want to dust off their DJ skills, there are a bunch of audio effects like reverb and "8-bit" so you can add a bit more spice beyond a smooth transition from left to right. Some of these are free (as is the basic app), but expect to shell out a buck or two for some of the more fancy pants audio accoutrements. The updated Pacemaker is available in the App Store starting today.