Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
NetSpeedMonitor - NetSpeedMonitor is a lightweight Network Monitoring Toolbar for your Windows Taskbar
Advanced IP Scanner - Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off. Download it Free.
NetWorx - NetWorx is a simple and powerful tool that helps you objectively evaluate your bandwidth situation.
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...