Here is a module I have been working on to display the status of devices on the network.
The original concept was to display an indicator of who was at home based on whether the persons phone was connected to the network (see below). As these devices have dynamic IP addresses, MMM-Ping was not an option so I temporarily created this module to show the status of these devices based on their MAC Address.
There are many other ways to use the module, including displaying (monitor?) the status of some/all devices connected to the network, though I’m not sure the MagicMirror it is the best place for this