Peter Wooster

This plugin allows developers to debug PHP errors.
Features for Developers
<ul>
<li>You can get call stack trace when PHP errors are triggered.</li>
<li>This is particularly helpful in finding errors that are triggered by the WordPress deprecation and 
doing_it_wrong code. These errors are reported in the WordPress core instead of at the location 
where the incorrect usage actually occurs. </li>
<li>You can set the error level from the Settings page, the default is trap Notice and Deprecation errors</li>
</ul>
Additional Features
There are no additional features supported by Simple Error Handler. The code is simple, small and well documented, 
so you can use it as a starting point for your own error reporting or logging plugin.

Simple Error Handler

A simple plugin that reports the call stack trace when PHP errors occur.

Paul

Gemini Labs

Black Bar is an unobtrusive Debug Bar for WordPress developers. It collects and displays errors, executed SQL queries, slow actions and hooks, theme templates, global variables, and provides a profiler.
How it helps you with development:
<ul>
<li>Debug your code with the Console</li>
<li>Inspect global variables (COOKIE, GET, POST, SERVER, SESSION, WP_Screen)</li>
<li>Measure performance of your code with the Profiler</li>
<li>View any PHP errors that occur when loading a page in the Console</li>
<li>View executed MySQL queries along with execution time and backtrace</li>
<li>View template files of the active theme in loaded order</li>
<li>View the 50 slowest action and filter hooks along with callbacks ordered by priority</li>
</ul>

Black Bar

Thank you for giving new life to BlackBox Debug Bar!

Not only the usefulness of this plugin, but the beautiful PHP coding leads me to write this review. I have learnt a lot from your code.

Developer must have

Il fait l'affaire haut la main, parfait ;-)
It did the trick, perfect ;-)


Indispensable / Essential

Black Bar is an unobtrusive Debug Bar for WordPress developers that attaches itself to the bottom of the browser window.

Simple Error Handler vs Black Bar