Michael Torbert

This plugin is great for someone needing to debug their own or another person’s WordPress site. It will collect and display and/or send debug information to an email address provided by the user. 
This is helpful for plugin or theme authors wanting to debug user’s sites.
Some features:
<ul>
<li>Displays system information</li>
<li>Emails system information</li>
</ul>
<h3>Arbitrary section</h3>
You may provide arbitrary sections, in the same format as the ones above. This may be of use for extremely complicated 
plugins where more information needs to be conveyed that doesn’t fit into the categories of “description” or 
“installation.” Arbitrary sections will be shown below the built-in sections outlined above.
<h3>A brief Markdown Example</h3>
Ordered list:
<ol>
<li>Some feature</li>
<li>Another feature</li>
<li>Something else about the plugin</li>
</ol>
Unordered list:
<ul>
<li>something</li>
<li>something else</li>
<li>third thing</li>
</ul>
Here’s a link to <a href="https://wordpress.org/" title="Your favorite software" rel="ugc">WordPress</a> and one to <a href="http://daringfireball.net/projects/markdown/syntax" title="Markdown is what the parser uses to process much of the readme file" rel="nofollow ugc">Markdown’s Syntax Documentation</a>. 
Titles are optional, naturally.
Markdown uses email style notation for blockquotes and I’ve been told:
<blockquote>
Asterisks for emphasis. Double it up for strong.
</blockquote>
<pre><code><?php code(); // goes in backticks ?>
</code></pre>

WordPress Debug

Displays and emails system information for debugging purposes for easy debugging of your own or a client/user site.

gilles66

Need to know which template is used by WordPress to display your pages in the front office ? 
This plugin simply does this.
Show the name of the php file of your theme used to display the current page.Need to know which template is used by WordPress to display your pages in the front office ? 
This plugin simply does this.
Efficient and very easy to install, it will show you in the admin bar the name of the php file currently used to display the current page. 
The color of the text is different regarding the origin of the template(the theme, a parent theme, or a plugin) 
(icon author :http://www.megaicons.net/iconspack-1096/45043/)

which template file

Show the name of the php file of your theme used to display the current page.

WordPress Debug vs which template file