NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.
Dell Technologies APEX - Dell Technologies APEX is a platform that delivers excellent cloud experiences to major businesses in the world.
Server Monitoring - A server monitor is a tool that monitors your server and website on close intervals and reports to you if it's inaccessible.
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.
mackerel.io - mackerel.io is a server and application performance monitoring platform.
AccelOps 4 - AccelOps 4 provides Today’s Data Centres access to IT Operation Analytics to make their hybrid, public, and private clouds more secure, efficient and reliable than before.