Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
TeamViewer - TeamViewer lets you establish a connection to any PC or server within just a few seconds.
Ettercap - Ettercap is a suite for man in the middle attacks on LAN.
AnyDesk - AnyDesk is the world's most comfortable remote desktop application. Access all your programs, documents and files from anywhere, without having to entrust your data to a cloud service.
tcpdump - tcpdump is a common packet analyzer that runs under the command line.
join.me - Instant screen sharing. Instant Aha!