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.
LightStep - We deliver insights that put organizations back in control of their complex software apps.
Oh Dear! - Website monitoring, without the hassle
Rootly - Rootly helps build a consistent incident response process by automating manual admin work like creating incident channels, Jira tickets, Zoom rooms, and generating postmortem timelines, all from within Slack.
Freshworks - Delight your customers, from wherever you are
updown.io - updown.io is a HTTP(S)/TCP/ICMP monitoring service which checks periodically the URL you want and reports back any anomaly.