In the first instance, perhaps an emergency broadcast to a pre specified recipient that can be sent very quickly in the cast of an accident. Effectively a preconfigured share location containing custom message. Perhaps it could have a function button that could then be added to the main screen, or even better a widget that could have two buttons, if you press both of them one after the other, the message could send.
While the above can be achieved by a seperate app, the following couldn`t. If the feature could be available when using track recording/guiding/navigation etc, and if a pre arranged checkin period was missed, the message would be sent, or if an estimated arrival time was passed etc