LambStatus - Serverless status page system which enables you to build a status page with minimum effort and cost!
cState - 🔥 Free & open source under MIT!
Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
Fyipe - Status page, monitoring and on-call made simple.
Cachet - Cachet is a free, open source status page for your API, service or company. Built with all of the features that you'd expect from a status page.
Upzilla.co - Upzilla.co alerts you when your websites, services, or applications have some issues with availability or performance. Quick and simple setup, multiple notification methods, and it's FREE.