Add a small GPS-unavailable icon (opposite side of the time from the Bluetooth icon) that shows whenever the phone's last location fix failed, and hides once it succeeds.
Add naked-eye deep-sky objects (Andromeda Galaxy, Orion Nebula, Pleiades, Beehive Cluster, Hercules Cluster, Double Cluster, Magellanic Clouds) to the sky view, shown once the sky is dark enough.
Initial release, experimental.