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.
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
NewRelic - New Relic is a Software Analytics company that makes sense of billions of metrics across millions of apps. We help the people who build modern software understand the stories their data is trying to tell them.
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.