So as your children are on their trick-or-treating route, you can use an iPad or a desktop computer to see exactly where they are going in real time. If your kids don't have their own iPhone, perhaps you can lend them yours and then turn on another app, Find My iPhone, which tracks your own phone in case you lose it.
Trick or Treating (iPhone, 99 cents) • With this app, children can input the contact information of all of their loved ones as well as police should they get lost and need direction to get home. All of the addresses are then displayed on a map.
SecuraFone (iPhone, Android, free, monthly service fee) • This full-featured app allows you to track the user in real time. But it also can send the parent alerts and notifications whenever the child with the phone is changing directions or speed. It also includes emergency contacts that can be accessed immediately.
GPS Phone Tracker (iPhone, Android, free) • Another tracker that parents can use to keep real-time tabs on their children. It also can log where they've been every couple of minutes so you can see the trail they're leaving behind.
Life360 (iPhone, Android, free) • Here is a robust GPS tracker with a lot of features including the ability to organize groups of friends you're following, a "panic" button your child can use if he or she is in trouble, and more. The free version has basic features, but there also is a premium service that provides a lot more.
Gone Out Later Folks (iPhone, $1.99) • This app allows kids to keep their parents up to date on where they are and where they are going. The child can take a picture and record the location of where he or she is at and send that information to parents.