Crisp Status Page - Monitor servers and let users know if something goes down.
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.
ContainIQ - Kubernetes native monitoring instantly
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Robusta - SRE Copilot for Kubernetes
Better Uptime - We call you when your website goes down