Seebz

Improve Page Permalinks. 
This plugin just adds .html to the permalink pages when needed. 
An option can prevent this action for specific pages.
<h4>Example</h4>
<ul>
<li>yourblog.com/page.html</li>
<li>yourblog.com/parent/</li>
<li>yourblog.com/parent/child.html</li>
</ul>
<h4>Compatibility</h4>
Not tested yet with all previous 3.0 WordPress version
Tests OK with the following plugins
<ul>
<li><a href="https://wordpress.org/extend/plugins/permalink-redirect/" rel="ugc">Permalink Redirect</a> (v2.0.4)</li>
<li><a href="https://wordpress.org/extend/plugins/cms-tree-page-view/" rel="ugc">CMS Tree Page View</a> (v0.6)</li>
</ul>

Improved Page Permalinks

Improve page permalinks by adding ".html" for final pages

Fubra

Steve

This plugin adds two areas of functionality: Global page, category or tag permalink structures and individual custom permalinks.
Options are added to the Permalinks Settings page allowing you to specify the structure for pages, categories, tags and authors.
By default – if custom permalinks are enabled – pages are accessible in the format <code>/page/</code> or <code>/parent/page/</code>.
You can modify this format in many different ways, for example:
<ul>
<li>Add an extension: <code>/%pagename%.html</code></li>
<li>Add a parent directory name: <code>/content/%pagename%/</code></li>
<li>Prefix the page name: <code>/page-%pagename%/</code></li>
<li>Or using a combination of the above.</li>
</ul>
This same format applies for categories, tags and authors, however the structure tokens differ:
<ul>
<li>Categories: <code>%category%</code> (E.g. <code>/category/%category%.html</code>)</li>
<li>Tags: <code>%post_tag%</code> (E.g. <code>/tag/%post_tag%.html</code>)</li>
<li>Authors: <code>%author%</code> (E.g. <code>/author/%author%.html</code>)</li>
</ul>
Each permalink base can be edited directly via these settings, for example using <code>/people/%author%.html</code> as the Author permalink structure will replace <code>/author/</code> with <code>/people/</code>.
If no prefix is found, permalinks will be prepended with a default (category, tag or author) – with the exception of pages.
Note: Ensure you have included the correct structure tag somewhere in the url.
Additionally, an option is added to the edit screen allow you to specify the permalink for an individual post or page.

Permalink Editor

Fully customise the permalink for an individual page or post and globally set the permalink structure for pages, categories, tags or authors.

Improved Page Permalinks vs Permalink Editor