taylor.mitchellstjoseph

This plugin adds an option in the admin toolbar to toggle WP_DEBUG on/off.
wp-config.php must be writable by the server and code must be in the default format/spacing – define(‘WP_DEBUG’, false);

Taylor's Debug Toggle

Toggle WP_DEBUG on/off through the admin toolbar

pantsonhead

Admin’s Debug Tool allows administrators to analyze page execution without executing/displaying for non-admin users. 
This can be useful when trying to track slow queries or badly performing plugins or widgets. 
The admin-only nature of this plugin can also be useful when trying to track issues that only occur on production servers.

Admin's Debug Tool

Admin-only tool for checking execution times and error output of current theme/plugins

Taylor's Debug Toggle vs Admin's Debug Tool