Sentry.io - From error tracking to performance monitoring, developers can see what actually matters, solve quicker, and learn continuously about their applications - from the frontend to the backend.
Phabricator - Phacility - Phabricator
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.
BugSnag - Not all bugs are worth fixing. Prioritize and fix software bugs that matter while improving software stability with every release.
RootCause - Record, Replay and Reproduce JavaScript Errors
AirBrake - Airbrake is the leading exception reporting service, currently providing error tracking.