List of free status stuff for developerππ½
If you're looking for all programming tools around status (not just free). Check this page List of status Programming Tools

Atlassian Status
Easily communicate real-time status to your users. Just like DigitalOcean, Dropbox, and Intercom.
Tag: status
100 subscribers 2 team members 2 metrics email notifications Slack notifications REST API
Sentry
Self-hosted and cloud-based application monitoring that helps software teams discover, triage, and prioritize errors in real-time.
Tag: status, monitoring, logging
1 User 30 day data retention 5K errors 10K transactions 1GB attachments

Allma
Don't just manage your incidents, collaborate on them with the entire company. Manage alerts, tickets, and timelines of events all from within the comfort of your Slack instance.
Tag: monitoring, status
Unlimited Users Slack Powered Incident Workflows 7 Day Data Retention

Open Source

Unlimited subs
Unlimited team