OneSignal - Customer engagement platform used by over 1 million developers and marketers; the fastest and most reliable way to send mobile and web push notifications, in-app messages, emails, and SMS.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Braze - Braze is an engagement platform that empowers growth by helping marketing teams to build customer loyalty through mobile, omni channel customer experiences.
Prometheus - An open-source systems monitoring and alerting toolkit.