ServerSuit - ServerSuit is a browser based program that enables remote Linux administration, monitoring, website hosting, and server setup automation.
GTmetrix - GTmetrix is a free tool that analyzes your page's speed performance. Using PageSpeed and YSlow, GTmetrix generates scores for your pages and offers actionable recommendations on how to fix them.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
PageSpeed Insights - PageSpeed is addon for ...
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.
WebPagetest - Run a free website speed test from multiple locations around the globe using real browsers...