debug-bar

Displays all the hooks( Actions and Filters ) for the current request in Debug Bar panel.

Debug Bar Rewrite Rules adds a new panel to Debug Bar that displays information about WordPress Rewrites Rules (if used).

Debug Bar Cron adds a new panel to Debug Bar that displays information about WP scheduled events.

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