Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
Toby - Better Than Bookmarks
Robodash - Cron and uptime monitoring dashboard
UptimeRobot App - Web, SSL, ports & Cron-jobs monitoring
Snooze Tabby - A simple way to snooze your tabs for later
Pulsetic - Pulsetic makes monitoring your SaaS products simple and easy with Status badges to show the status of the site without changing pages and you will also be alerted when your site goes down.