Correct me if I am wrong, but it sounds like you have a security app that has multiple applications but you do not know what market is the best one for you to focus on first ( i.e. Beachhead market).
After doing a quick look at your website it looks like your main target would be parents that would install the app on their child's phone. I just clicked on your link to go to the iPhone App Store and it took me to a form to submit my information. Since you do not have the iPhone app available yet I would recommend starting a kickstarter campaign to start getting preorders and you can do certain levels and quantities such as individual and family packages or larger business or school packages. And then use social media advertising and targeting to parents.
I think there's also a market for individuals with special needs that parents or facilities need to monitor their whereabouts. However I don't know how large that market would be and it would probably be something to focus on down the road.
I hope that helps and good luck .