EasyCron - Get frustrated with Cron on your server? Hosting limits your Cron use?
crontab guru - The quick and simple editor for cron schedule expressions by Cronitor
Cronly - Keep track of your cron jobs and SSL certificates. Don't let them fail unnoticed.
SetCronJob - web based cron job service
Cronitor - Monitor cron jobs, micro-services, daemons and almost anything else, no setup required. Easier cron troubleshooting and no more silent failures.
Posthook - Simple, Robust Job Scheduling For Your Application