Dougal Campbell

By default, the only way to see how a new theme looks on your site is to 
activate it, making it visible to everyone who visits. With this plugin, it 
is possible to view how a new theme looks without activating it.
<h3>TODO</h3>
Possible future enhancements:
<ul>
<li>Add an options screen.</li>
<li>Allow choice of theme to preview from a known list of installed themes.</li>
<li>Provide persistent previews by setting a cookie.</li>
<li>Restrict preview ability by user Roles/Capabilities.</li>
<li>Child-theme friendliness.</li>
</ul>
<h3>Notes</h3>
May not work properly with child themes. This is because it will not be able 
to inherit from the parent theme as it normally would.

Theme Preview

Allows you test how a theme looks on your site without activating it.

tonnaer

A free, small (only 13Kb) flash slide show widget, that can easily be integrated 
into your WordPress 3.4 website, and can be entirely (or almost) personalized 
through a bunch of parameters.
New features: 
* A title can be set 
* Slides can be loaded through a proxy, enabling cross domain image loading 
* The transparancy of the slide show’s background can be set 
* A watermark image, its transparancy, position and full-window display can be set 
* A new border type: image 
* The possibility to set a different target window for each slide 
* The possibility to load all images (jpeg, gif and png) in a folder 
* The possibility to use dynamic xml creation, which should resolve any write permission problems 
* The possibility to choose if images must be resized to fit the slideshow window
Other features: 
* also works if you’ve given <a href="https://codex.wordpress.org/Giving_WordPress_Its_Own_Directory" title="Giving WordPress its own directory" rel="nofollow ugc">WordPress its own directory</a> 
* works with redirects 
* works with permalinks 
* height and width can be set 
* 28 transition types 
* links can be enabled (one for the whole slide show, or one for each slide) 
* slides can be shown in forward, backward or random order 
* border style, color, width and transparancy can be specified 
* caption can be text or image 
* caption can be the same for the whole slide show, or a different one for each slide 
* caption characteristics (position, style, font, fontsize, color, transparancy, etc) 
 can be specified 
* you can have more than one slide show on your pages. 
* etc.

Creative Clans Slide Show

A free widget to use the Creative Clans Slide Show in your Wordpress website.

Theme Preview vs Creative Clans Slide Show