Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
Venmon - Compact size system resources monitoring utility and multi-ping tool for Windows
MenuBar Statistics - MenuBar Statistics is a lightweight app that sits quietly in your menu bar of macOS and displays computer information such as CPU, Disk, and Network, which is updated every 5 seconds.
Taskbar Meters - Incredibly simple meters that live in the Windows 7 task bar.
RPi-Monitor - RPi-Monitor is a tool that provides all the connected system peripherals properties and current metrics.
Mousotron - Mousotron is a mouse and keyboard activity monitor and keeps statistics of your mileage. It's like an odometer or tripometer for your mouse cursor.