you can install Refog Keylogger www.refog.com/keylogger.html on your kids' computer. This will give you the opportunity to track all the activity of children on the computer. You will know what sites and videos your children use, as well as who and what they are talking about on social networks
To keep track of the kids all day long, I decided to start using phone tracker www.hoverwatch.com . This is an application created specifically for smartphones. It has a number of interesting functions and, most importantly, it helps me find out the location of my children.