For travellers planning to visit Iceland we highly recommend the official app for Iceland’s emergency service, 112.
This app has two major functions
One: “Check in” button to send your location, but 112 emergency service will log you last 10 locations.
Two: “Emergency” button to send your location via SMS to 112, with the phones GPS location, before calling 112.
More info about the app is on safetravel.is
The app can be downloaded here