FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.
PuTTY - Popular free terminal application. Mostly used as an SSH client.
Network Lights - Network Lights is a Windows program, which blinks keyboard LEDs (Light Emitting Diode) indicating outgoing and incoming network packets on network interface.
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
TrafficMonitor - TrafficMonitor is a network monitoring suspension window software in Windows.
iTerm2 - A terminal emulator for macOS that does amazing things.