ngrok - ngrok enables secure introspectable tunnels to localhost webhook development tool and debugging tool.
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.
Portmap.io - Expose your local PC to Internet from behind firewall and without real IP address
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Vercel - Vercel is the platform for frontend developers, providing the speed and reliability innovators need to create at the moment of inspiration.
Better Uptime - We call you when your website goes down