Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
Cronitor - Monitor cron jobs, micro-services, daemons and almost anything else, no setup required. Easier cron troubleshooting and no more silent failures.
WebGazer - Monitor your website's availability with WebGazer, review its performance and get instant notifications when your website goes down. No installation required and free plan available.
UptimeRobot App - Web, SSL, ports & Cron-jobs monitoring
Troops Slack Sales Gong - The most customizable Salesforce Gong in Slack
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.