We know that there are iPhone accessories which can be controlled by apps, but what happens when you plug one in without having the corresponding app? Turns out it'll trigger a download prompt.
Choosing to download the app at the prompt will lead users to a brand new "For This Accessory" page in the App Store from which they can select the app they need. We've only got Griffin's iTrip accessory and app as an example for now, but it seems like this is showing some great third-party accessory support by Apple. [iLounge via Tech Eruption]