Nav console SDK? Adding software?

Is there an Software Development Kit available to add functionality to the nav/MFD display?

I'd love to write an app to do things with my iPhone, like robust control of music playback, or pushing email/twitter notifications to the screen, or pushing geo coordinates from my phone to the nav as a new destination.

If there is, what language(s) does development happen in? How do I install code? Does code need to be signed?

Thanks in advance, and sorry if this question has been asked. I checked and didn't see anything.