Of course, first of all is [Debug Bar](https://wordpress.org/plugins/debug-bar/)


[Monster Widget]
(https://wordpress.org/plugins/monster-widget/)

[Developer]
(https://wordpress.org/plugins/developer/)

	
[Say What?]
(https://wordpress.org/plugins/say-what/)

[Show Curent Template](https://wordpress.org/plugins/show-current-template/)
A WordPress plugin which shows the current template file name, the current theme name and included template files' name in the tool bar.