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.

Rollbar - Rollbar collects errors that happen in your application, notifies you, and analyzes them so you can debug and fix them. Ruby, Python, PHP, Node.js, JavaScript, and Flash libraries available.

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.

CatchJS - Unbloated, yet feature rich. CatchJS provides JavaScript Error Tracking the way it should be.

AppSignal - We monitor the software that makes your customers happy.

ErrLytics - Javascript error reporting and performance monitoring tool