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.
Infoblox DDI - Infoblox’s industry leading integrated, centrally managed approach to delivering enterprise-grade DNS, DHCP, and IP address management (DDI) supports current and evolving IT needs.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Efficient IP DNS Security - Efficient IP DNS Security is a 360 degree DNS security and network protection solution that fills the DNS security gap left by traditional security systems.
Better Uptime - We call you when your website goes down
Cloudflare DNS - Install the free app that makes your phone’s Internet more fast, private, and reliable.