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.
Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
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.
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
Zabbix - Track, record, alert and visualize performance and availability of IT resources
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.