Suprvise is a real-time health monitoring and errors tracking dashboard.
Site Down - Site down outage and downtime reports from SiteDown.co
WebGazer - Monitor your website's availability with WebGazer, review its performance and get instant notifications when your website goes down. No installation required and free plan available.
Is it up? - A simple tool to check if a website or ip address is up or down.
Oh Dear! - Website monitoring, without the hassle
downinspector.com - Find out if a website is down for everyone or just you.
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting