Snap

Snap is a network scanner that shows you the devices and then the services of each of those devices. It's a great tool for a network tech, or the inquisitive, to help you keep track of the devices on your network.

For non tech though -- it can be interesting when on public networks. I'll let your imagination roam there.

The network and host scanning while not speedy but pretty fast and fairly accurate in testing on my home network. If this is something you could use, it's a great option.