uBar - The Dock replacement for the Mac.
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.
Pock - Display the macOS Dock in your Touch Bar
UptimeRobot - Free Website Uptime Monitoring
Notification Shortcuts - Fastest way to close, open, or reply to notifications on Mac
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring