Wake On LAN Ex 2 - Free software from Joseph (AKA BootBlock) of http://www.bootblock.co.uk
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
Advanced Port Scanner - Advanced Port Scanner is a fast and free software for port scanning.
Fing - Discover which devices are connected to any Wi-Fi network, map devices, detect intruders, assess...
WOL Magic Packet Sender - A free magic packet sender for Windows - wake-up computers with the touch of a button.
Wireless Network Watcher - scans your wireless network and displays the list of all computers and devices that are currently connected to your network.