Clockwork - php dev tools in your browser - server-side component
The DebugBundle allows greater integration of the VarDumper component in the Symfony full-stack framework.
The VarDumper component provides mechanisms for walking through any arbitrary PHP variable. It provides a better dump() function that you can use instead of var_dump().
The Debug component provides tools to ease debugging PHP code.
Bugsnag notifier for the Laravel PHP framework. Monitor and report Laravel errors.
Implementation of PHP Console for WordPress.
Tracy: the addictive tool to ease debugging PHP code for cool developers. Friendly design, logging, profiler, advanced features like debugging AJAX calls or CLI support. You will love it.
Debug Bar Extension for the Timber Library
A Guzzle middleware that lets you log HTTP requests in the PHP debugbar timeline.