Obzrv.it - Obzrv.it is a universal web monitoring service.
Freshworks - Delight your customers, from wherever you are
WebARX - Website Protection, Managed Website Security & Website Monitoring
UptimeRobot - Free Website Uptime Monitoring
Visualping - Visualping is the easiest to use website checker, webpage change monitoring, website change detector and website change alert software of the web. Read more about Visualping.
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting