Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Zabbix - Track, record, alert and visualize performance and availability of IT resources
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
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.
Plivo - Plivo simplifies your customer engagement.
Prometheus - An open-source systems monitoring and alerting toolkit.