digitalissimo

If you need to get the information from another site or your site using JSON API (https://wordpress.org/plugins/json-api/) you can use this plugin. 
For slideshow this plugin use Cycle2 (http://jquery.malsup.com/cycle2).
<h4>Shortcode</h4>
<pre><code>[getapi url="www.mysite.com" limit="5" type="[CYCLE or LIST]"]:
</code></pre>
<ul>
<li>
url: url before ?json=get_recent_posts
</li>
<li>
limit: number element of json result
</li>
<li>
type: “Cycle” is a slideshow of thumbs or “List” is the list of post titles
</li>
</ul>

Get Json Api

Retrieve the results of the API of a site that uses the plugin JSON API

Pete Nelson

Allows tweaking of several REST API settings
<ul>
<li>Disable the REST API</li>
<li>Remove WordPress core endpoints</li>
<li>Require authentication for core endpoints</li>
<li>Force SSL</li>
<li>WP-CLI commands: wp rest-api-toolbox</li>
</ul>
Find us on GitHub at https://github.com/petenelson/wp-rest-api-toolbox
(Creative commons toolbox image provided by James Tworow https://www.flickr.com/photos/sherlock77/)

REST API Toolbox

Allows tweaking of several REST API settings

Get Json Api vs REST API Toolbox