Nick Halsey

This plugin creates a fullscreen slideshow that displays randomly-selected pictures from your media library. Designed to display pictures related to your business/organization in the background at an event or in your office, there is no need to configure any settings or controls. Image captions/descriptions are automatically displayed as well, and can be configured based on your needs.
Once activated, you can view the slideshow by visiting <code>http://yourdomain.com/slideshow</code>. All JPEG images will be displayed (since .jpg is best for pictures, while .png and .gif are typically used for graphics).
Please note that it is not currently possible to pause the slideshow or go back; the slideshow is not designed for personal viewing. However, clicking/tapping on the image will open its attachment page in a new tab, allowing images to be contextualized or edited easily.
The slideshow can also be embedded into your site via a widget or a shortcode.
You can control some options by adjusting the url of the slideshow. Parameters are controlled via query string (and widget options and shortcode attributes).
<ul>
<li><code>size</code> is the size of the image to load, either <code>thumbnail</code> (discouraged), <code>medium</code>, <code>large</code>, <code>full</code>, or <code>auto</code>, which uses medium or large depending on <code>wp_is_mobile()</code>.</li>
<li><code>year</code> is the 4-digit numeric year in which the images were published.</li>
<li><code>month</code> is the numeric month in which the images were published (between 1 and 12), typically but not necessarily used in conjunction with <code>year</code>.</li>
<li><code>mode</code> defines a subset of images to use, such as <code>featured</code> for featured images only.</li>
<li><code>captions</code> controls the captions display: either <code>auto</code>, <code>none</code>, <code>title</code>, <code>titlecaption</code>, <code>caption</code>, or <code>description</code>. Caption data is read from the image attachment post and can be updated in the media library.</li>
</ul>
Using all options, for example: 
http://example.com/slideshow?size=full&year=2014&month=4&mode=featured&captions=titlecaption
You can see it in action <a href="http://uscasce.com/slideshow" rel="nofollow ugc">here</a>.

Content Slideshow

This plugin creates a fullscreen slideshow that displays randomly-selected pictures from your media library. Designed to display pictures related to y …

foter

Foter is the easiest and fastest way to add Creative Commons photos to your blog. We find and host millions of photos from many online sources and make them available to be included in your blog posts.
This plugin lets you seach, manage and add Creative Commons photos to your blog posts in a very simple way.
Some of the features:
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Image resizing: flexibility and preview feature
</li>
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Image download: you can use plugin or simply download image from foter.com website
</li>
<li>
Attribution info: all attribution information is automatically added to the photo, so you don’t need to add it manually
</li>
<li>
Search photos: you can search photos by tags or keywords
</li>
<li>
Speed: very fast and easy to use
</li>
</ul>
Website: <a href="http://foter.com/" title="Free Stock Photos Foter.com" rel="nofollow ugc">Free Stock Photos Foter.com</a>

Free Stock Photos Foter

This plugin lets you easily search, manage and add free photos (more than 180 mln of them) to your blog posts.

Content Slideshow vs Free Stock Photos Foter