InfluxData - Scalable datastore for metrics, events, and real-time analytics.
Rave Alert - Rave Alert is a multi-modal emergency notification system used by state and local governments, colleges, hospitals and universities.
TimescaleDB - TimescaleDB is a time-series SQL database providing fast analytics, scalability, with automated data management on a proven storage engine.
DialMyCalls - The easy to use mass and emergency notification platform. Send a phone call, text message or e-mail to your entire list of people in seconds.
Prometheus - An open-source systems monitoring and alerting toolkit.
Call-Em-All - Call or send messages to friends and family members as well as other people who are online. The app allows you to create a message and send it out to multiple devices and pages.