Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
UptimeRobot App - Web, SSL, ports & Cron-jobs monitoring
UptimeRobot - Free Website Uptime Monitoring
Cronitor - Monitor cron jobs, micro-services, daemons and almost anything else, no setup required. Easier cron troubleshooting and no more silent failures.
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.
Cronhub - Cronhub helps you to easily monitor all your cron jobs in a beautiful dashboard. It alerts you when your cron job doesn't run on time or it fails.