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.
Catchpoint - Catch issues before they impact your business
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Instrumental - Real-Time Application & Performance Monitoring
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
ThousandEyes - ThousandEyes is a Network Intelligence platform that delivers visibility into every network your organization relies on.