SolarWinds Pingdom - With website monitoring from Pingdom, you will be the first to know when your website is down. No installation required. 14-day free trial.
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
AppDynamics - Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.
New Relic Synthetics - Use New Relic Synthetics monitoring to simulate user flows, monitor APIs, and proactively monitor each of your digital touch points.
Zabbix - Track, record, alert and visualize performance and availability of IT resources