Different Single Post Template per Category
Lets a classic theme use single-cat-{slug}.php for posts in a given category, for example a recipe layout for posts filed under Recipes, falling back to the normal template.
Snippet Library
Developer snippets for WordPress
Snippets for developers: debugging helpers, custom cron schedules, body classes, REST API tweaks and admin tools for checking hooks and queries. Building blocks for people who write code for WordPress every day.
Keep Plugin Deprecation Notices Out of debug.log
Stops PHP deprecation notices coming from plugins and themes from filling debug.log, so the real warnings and errors you are looking for stand out while debugging.
Log Deprecated and "Doing It Wrong" Notices With Their Source
Writes every deprecated function, argument, hook or "doing it wrong" notice to the PHP error log with the plugin or theme file that caused it, even when WP_DEBUG is off.
Log Slow Page Loads
Writes a line to the PHP error log for every request that takes longer than a set number of seconds, with the URL, time, memory and query count.
Measure How Long Code Takes
Adds wpide_timer_start() and wpide_timer_stop() helpers that measure the time and memory a piece of code uses and write the result to the PHP error log, to find slow functions.
PHP Info Screen for Administrators
Adds a Tools > PHP Info screen showing the full phpinfo() report (extensions, limits, configuration), handy when a host's control panel does not show it.
Register Page Templates From a Folder Outside the Theme
Adds every PHP file in wp-content/page-templates/ to the page Template menu of classic themes, so custom layouts survive theme switches and updates.
Send PHP Values to the Browser Console
Adds a wpide_console() helper that prints any PHP variable to the browser's developer console for administrators, so you can inspect data without breaking the page layout.
Show PHP Errors to Administrators With ?debug=1
Lets administrators see PHP warnings and notices on screen by adding ?wpide_debug=1 to any address, while visitors and other users never see them, even with WP_DEBUG_DISPLAY off.
Show PHP Version, Memory and Queries in the Admin Footer
Replaces the WordPress version in the bottom right of admin screens with the PHP version, peak memory use and database query count of the current page.
wp-config.php Settings Overview Under Tools
Adds a Tools > Config Constants screen that shows the value of important wp-config.php settings, such as debug mode, memory limits, cron, caching and file editing, without opening the file.