Whoever wrote this app understood two simple business techniques:

1) In non-technological industries there are golden opportunities for software developers. A small app like this can make a huge difference for first responders.

2) Sometimes it pays to target small, specific niches instead of the entire market. Even if your potential users make up 0.1% of all users (e.g. iPhone owners) your specificity can pay off by capturing all of that 0.1%.