Amazon CloudFront - Amazon CloudFront is a content delivery web service.
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.
Imperva Cloud Application Security - Deploy your applications and data where you want. When you want. Imperva keeps them secure in the cloud, on premises, and in hybrid clouds.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
GoDaddy Website Security - GoDaddy’s Website Security program monitors and protects your website from malware and other potential security breaches, keeping your site running lightning-fast.
Better Uptime - We call you when your website goes down