Cronitor - Monitor cron jobs, micro-services, daemons and almost anything else, no setup required. Easier cron troubleshooting and no more silent failures.
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.
ExternalCronJobs - You can now manage your cron jobs using this application
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Cronit App - Schedule and run cron jobs online from your browser, for free, with our online cronjobs service.
Better Uptime - We call you when your website goes down