UptimeRobot - Free Website Uptime Monitoring
Cruz RMM - Cruz RMM is an ideal solution for Managed IT service providers on the lookout for a remote management product to mechanize and track the operations of their user base.
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.
Dell Technologies APEX - Dell Technologies APEX is a platform that delivers excellent cloud experiences to major businesses in the world.
RapidSpike - RapidSpike is a reliability, performance and security monitoring service for transactional websites. Using next-generation synthetic monitoring & deeper than ever before data, RapidSpike is for businesses serious about protecting their online revenue
LogicMonitor - LogicMonitor is the SaaS performance monitoring platform for the world's best IT teams. Deploy Fast, Monitor More, Improve Ops.