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.
Pages by Headlime - AI-powered landing page builder (GPT-3 + Tailwind)
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Landing Pages in MailChimp - Easy to build, custom landing pages for free
Better Uptime - We call you when your website goes down
TinyFaces - Free crowd-sourced avatar gallery including Sketch plugin