The end result is that I have an automated solution to monitor whether my kids used any form of networked devices such as the TV, tablet, PlayStation, etc, when they are not supposed to.
Let's start off with the premise of this experiment. There's a limited subset of home automation devices in the house, but the number of networked devices is much greater. Such devices in my house would include my TV, TV Box, sound system, PlayStation, tablets, phones, desktops and laptops.
Even older non-smart TVs would have an Ethernet connection for simple DLNA functions or updating of firmware.
For the technical details, by setting a static IP to the device in your router, or decoding what is the device's MAC address, a micro computer like the Raspberry Pi is able to tell exactly which device goes online. The open nature of the SmartThings interface means that I can then get the Raspberry Pi to send messages to SmartThings such that the real-time information and post-reports can be viewed from the SmartThings platform. The screenshot below shows a sample of how my Raspberry script just comprises of simple fping and curl commands.