Stephen AfamO

This plugin allows you to use any HTML or PHP file as the template for any page or post.
Simply upload the file and select it. 
You can upload custom js and css files into the media library and link to them from the HTML file.
Options:
<ul>
<li>Overwrite All: You overwrite the entire theme and use your custom file</li>
<li>Overwrite Content: Keeps the header, footer, sidebar, e.t.c. Simply overwrites the body of the page or post</li>
<li>Above Content: Your custom content is simply added to the top of the page content</li>
<li>Below Content: You custom content is placed just beneath the page content.</li>
</ul>
<h4>Adding support for custom post types</h4>
By default the pulugin works with pages and posts, however, go to the settings to enable it on any other registered post type.
use the <code>hppp_post_types</code> filter to add more post types.
Like this:
<pre><code> public function post_type_modify ($post_types) {
 $post_types[] = 'custom_post_type';
 return $post_types;
 }

 add_filter( 'hppp_post_types', 'post_type_modify' );
</code></pre>

Custom HTML/PHP Post Templates

I use this on a couple sites I own and it works wonderfully.
I hope you can find it useful. 

Works like a charm

Use your HTML or PHP files for any page or post.

vegacorp

Jose Vega

Green Jay Media

<ul>
<li>
Easily create custom page templates for any theme.
</li>
<li>
Do you want to use a WordPress theme that doesn´t have a full width page template? Add any template to your theme with WP Page Templates
</li>
<li>
You can add a left and/or right sidebar. You can even add above or below main content.
</li>
</ul>
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/c2KBLNvQWzA?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>
<h4>Features</h4>
<ul>
<li>
Add left sidebar to pages
</li>
<li>
Add right sidebar to pages
</li>
<li>
Add left and right sidebar to pages
</li>
<li>
Add sidebar below the content
</li>
<li>
Add sidebar above the content
</li>
<li>
And more…
</li>
</ul>
<h4>Go Premium</h4>
If you need more features, our premium version allows you to:
<ul>
<li>
Hide header and footer for Landing Pages
</li>
<li>
Hide header and footer for WooCommerce Products
</li>
<li>
Hide header and footer for Events or any Post Type
</li>
<li>
Create full width posts
</li>
<li>
Create full width WooCommerce products
</li>
</ul>
<a href="https://wppagetemplates.com/premium-upgrade/?utm_source=wp.org&utm_medium=web&utm_campaign=free-plugin" rel="nofollow ugc">Try the premium plugin for free for 7 days</a>

WP Page Templates

Create full width pages, add left or right sidebars, add above or below content sidebars.

Custom HTML/PHP Post Templates vs WP Page Templates