PagerDuty - Cloud based monitoring service
Metric.live - Real-time and advanced periodic alerts for Google Analytics.
One Call Now - One Call Now's message notification delivers automated phone calls, SMS text messages and emails within moments to any group.
Alfred - Alfred is an award-winning app for macOS which boosts your efficiency with hotkeys, keywords, text expansion and more. Search your Mac and the web, and be more productive with custom actions to control your Mac.
OpsGenie - Alerting and On-Call Management for Dev&Ops Teams
Keysmith - Create custom keyboard shortcuts for your Mac and the web