Child ID, the first app from the FBI, is a bit late to the party. Using the app, parents can store key information about their children, including height, weight, and even photographs- that can be shown to authorities in the event that their kids go missing. The app also offers advice on what to do in the moments just after kids go missing. That can be vital information in many situations.
And in the event that you are (rightfully) concerned at the prospect of the FBI storing all the information you enter about your kids - don't be. The agency says that it does not collect and photos or information stored on the app - that is, until you send the information to authorities. Likewise, looking at the reviews of those who have used the app so far, it is clear that another major hold up for the program is that it lacks a fairly basic and sensical feature: password protection. So if you are uncomfortable with storing your kid's info in an unsectured app, It might be a good idea to hold off on downloading Child ID until the FBI implements the feature.
Sadly for Android parents, the app is currently only available for the iPhone. The FBI says its aiming to bring the app to other devices within the next few weeks and months.
In any case, the app is clearly one one hopes never to use. But is never bad to be prepared.