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While full-on inter-app communications — similar to Android’s intents or Windows Phone’s contracts — were high up on many geek’s iOS 7 must-have list, nothing of the sort was announced by Apple at WWDC 2013. Well, almost nothing. Apple has added inter-app communications to iPhone and iPad, they’ve just restricted to one very specific type: Inter-App Audio.
Here’s how the public-facing portion of Apple’s developer portal describes it:
Now your apps can make beautiful music together. With Inter-App Audio, apps can register their audio streams to share with other apps. For example, a series of apps could publish audio streams of instrument tracks while another uses the combination of these streams to compose a song. Inter-App Audio also provides for MIDI control of audio rendering, remotely launching other registered Inter-App Audio apps and more.
Apple raised some eyebrows earlier this year when they updated GarageBand to support Audiobus, a third-party solution for doing pretty much what Apple is doing now with Inter-App Audio. In a post on their Tumblr blog, Audiobus commented:
We’re excited about the great work the Core Audio team have done on the new functionality, which has some terrific features that only a team at Apple with system-level access could achieve. It validates the work we’ve been doing with Audiobus, and will pave the way for some great user experiences to come.
How exactly iOS 7 apps will take advantage of the new Inter-App Audio, where Audiobus will fit in a post-iOS 7 world, and what kind of music artists will be able to create using the new tools — well, we’ll know come the fall. At the very least, we should see a new version of GarageBand, along with a slew of other audio app updates, followed by a whole lot of new audio workflows.
As to whether or not Apple will ever expand Inter-App to include all the many different types of files and data power-users want to move around their mobile devices, it looks like that’ll have to wait and see…
iOS 7: Everything you need to know iOS 7: Discussion forum 
