Trampoline

Trampoline is the codename for the iPhone 5's OTA Update Enabler. iOS 6.0 on the iPhone 5 apparently included a bug that prevented OTA updates from occurring properly. As a result, Apple made the OTA update process a little less straightforward.

Trying to perform an OTA update informs you about the updater app, and how to obtain it.

Process

Spawn by update daemon (causes elevated privileges)
Mount Disk Image /Applications/iOSUpdater.app/iOSUpdaterHelper.dmg at /Developer
Copy contents off (essentially cp -r /Developer/* /)
Reboot
Daemon runs and patches files
Daemon deletes Trampoline
Reboot

iOSUpdater.app Notes

The app can be installed on a device via iTunes.
iOS Updater can't be deleted on the device, but can be removed via iTunes.
The app appears to require elevated (root) privileges.
iOS Updater is deleted on successful update.
Among with iOSUpdaterHelper.dmg, in iOSUpdater.app, there is its signature. This prevents hackers from replacing it with an unofficial image.