Interesting, but it seems that manual intervention is required to do the steps needed. I don't think an app installed from the store can do these steps on it's own.
It exploits a vulnerability related to the management of the microSD card, which allows wholesale replace an application by another, while preserving and exploiting the Capabilities of the one that was replaced.
Normally I'd leave this thread open as it was created first, but the other thread has accumulated more information, so I've decided to close this one instead. Sorry to the OP for not catching the second thread earlier.