Cronitor - Monitor cron jobs, micro-services, daemons and almost anything else, no setup required. Easier cron troubleshooting and no more silent failures.

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.

Robodash - Cron and uptime monitoring dashboard

Healthchecks.io - Monitor your cron jobs and scheduled tasks, get notified when they fail.

Dead Man's Snitch - Monitor Cron Jobs and Windows Scheduled Tasks with ease.

crontab guru - The quick and simple editor for cron schedule expressions by Cronitor