I use New Relic, there’s Uptimemontior, etc.
I also asked @emmanuel a while ago if he could ask Atlassian to enable their status page so other status pages can add it as a third-party component. So, if you’re using Atlassian Statuspage Bubble’s component status will reflect on your status page.
Instatus also supports this.
Ref: Making Bubble Statuspage Components Available as Third-Party Component on all Atlassian Statuspages