Sentry is a realtime event logging and aggregation platform. It specializes in monitoring errors and extracting all the information needed to do a proper post-mortem without any of the hassle of the standard user feedback loop.

You can know immediately when things happen in your application. Engage users before they have a chance to report a problem. Spend more time where it matters, rather than investing into low-impact issues. Drop-in integration for more than a dozen platforms, including Python, PHP, Ruby, Node.js, and Java. Sentry is open source software. You can grab the source code on GitHub.

Requirements: -
Demo: https://github.com/getsentry/sentry
License: License Free