TL:DR; Wayk Now lets you take control of a remote computer, or allow an authorized user to take control of your computer.
Wayk Now lets you take control of a remote computer, or allow an authorized user to take control of your computer. Wayk Now is free for personal and commercial use and currently available on Windows, Max OS X and Linux.
Wake-On-LAN Sender can be used to turn on remote computers sending magic packets (UDP). This freeware utility also allows to identify MAC addresses of LAN computers.
Remote Desktop Screenshot allows you to capture remote desktop screenshots. You can see all users' desktops at once. With built-in scheduler you can set time for update screenshots for all computers or for certain computers.
Packet sniffer (network analyzer or network sniffer) for network monitoring and troubleshooting. It allows you to monitor network operations, isolate & solve network problems, identify network bottleneck & bandwidth use, and replay packets.