thunderbax

The plugin add a custom page in your admin dashboard where you can show html code to editors. 
You can edit the html text directly in a box place in option page with a WYSIWYG editor. 
All html, javascript, css are supported. 
You can also insert Youtube videos or images.
Related Links:
<ul>
<li><a href="http://www.thunderbax.com/?page_id=767" title="WP Admin Custom Page Plugin for WordPress" rel="nofollow ugc">Plugin Homepage</a></li>
<li><a href="http://www.thunderbax.com" title="Author Homepage" rel="nofollow ugc">Author Homepage</a></li>
</ul>

WP Admin Custom Page

The plugin add a custom page in your admin dashboard where you can show html code to editors.

kr4ft3r

Multisite support added in v0.6!
Notice: this plugin will not have further major updates. If interested in new features, please upgrade into this compatible replacement: https://wit.rs/wp-plugins/wit-custom-output 
After uninstalling the WPCHTMLP and installing WIT Custom Output, your old custom pages will still work, but with better interface, more features and regular updates.
WP Custom HTML Pages plugin has two functionalities:
1 – Create a custom HTML document output at a custom permalink address, completely bypassing WordPress templating. This is useful in cases when you just want to output some HTML without uploading the page to the server.
2 – Create a shortcode which outputs your custom HTML.

WP Custom HTML Page

Display full custom HTML on custom permalink address, or put it inside content as a shortcode.

WP Admin Custom Page vs WP Custom HTML Page