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.

Netumo - Ensure healthy website performance, uptime, and free from vulnerabilities. Automatic checks for SSL Certificates, domains and monitor issues with your websites all from one console and get instant notifications on any issues.

PingTurk - PingTurk is a cloud-based platform to monitor website from many locations and behind different networks, reporting on customers experience.

AppZero - AppZero is a monitoring and migration tool that allows users to keep track of different applications and servers in both simple and complex IT environments.

StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring

RedGate SQL Monitor - SQL Monitor helps you and your team find issues – before they become problems