AirBrake - Airbrake is the leading exception reporting service, currently providing error tracking.
Errsole - Collect, store, and visualize logs with a single module
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.
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.
GlitchTip - GlitchTip is an open source, Sentry API compatible error tracking platform.
Lightrun - Dynamically instrument Live Applications from your IDE