Rohan Kapoor

This plugin was created to allow any page to be viewable from the WordPress/MU Admin Panels. You can use it to view a page before you submit it or to just look at anything on your blog. The beauty of it, is that because it uses iframes you can have it show you anything on any domain! For example, I use it to keep track of my forums while I am writing a post/page and to see if I need to add anything based on the current discussions.
Those of you who use my <a href="https://wordpress.org/extend/plugins/new-bbpress-admin/" rel="ugc">New bbPress Admin</a> plugin might notice a few similarities between the plugins. The truth is that the functionality of the two is so similar, that the codebase is also 99.9% the same. The only differences are in the variables (so that both can be uses simultaenously with no problems) and some of the text, so that you can tell the difference between the two of them. There is no ill effect if both are used at the same time. Options entered in one will be kept separate from the other.

WordPress Live Preview

Allows you to see any Page from the Admin Section. Useful to Check How Something Looks Before Submitting it!

Mike Martel

With Live Theme Preview, you can select a theme in an interface based on the Theme Customizer in WordPress. A sidebar shows all installed themes (or, with multisite – allowed themes), to preview, edit or activate.
See the screenshot, or install and try it for yourself.
If you want to help develop this plugin, visit the <a href="https://github.com/mgmartel/WP-Live-Theme-Preview" rel="nofollow ugc">GitHub repo</a>.
<h4>Features</h4>
<ul>
<li>Seamless integration with Theme Customizer</li>
<li>Supports child themes</li>
<li>Multisite compatible</li>
<li>Relocates WP ‘Themes’ interface to “Manage Themes” under Appearance</li>
<li>Customize before activate, back button redirects to Live Theme Preview</li>
</ul>
Live Theme Preview is part of <a href="http://trenvo.com" rel="nofollow ugc">Live Admin</a> and works great with <a href="https://wordpress.org/extend/plugins/live-dashboard/" rel="ugc">Live Dashboard</a>, <a href="https://wordpress.org/extend/plugins/wp-getting-started/" rel="ugc">WP Getting Started</a> and <a href="https://github.com/mgmartel/WP-Live-Editor" rel="nofollow ugc">Live Editor</a>

Live Theme Preview

Live Theme Preview allows users to preview themes on their own website before customizing or activating them.

WordPress Live Preview vs Live Theme Preview