px app - ps and top for human beings
iStat Menus - "An advanced Mac system monitor for your menubar."
MenuMeters for El Capitan - MenuMeters for OS X El Capitan 10.11 (and later)
Windows Task Manager - Need assistance with your Microsoft product? Find helpful articles for Windows, Office, Microsoft Account, Microsoft Store, Xbox, and more.
Stats - Simple macOS system monitor in your menu bar.
IPtraf-ng - iptraf-ng is a fork of original iptraf-3.0.0.