yorik

This plugin allows to place widgets on your sidebars, that fetch the contents of one or more RSS feeds, combine them by date if there is more than one, and display the thumbnail images that are included in the feeds items. You can give the widget any number of feeds, and limit the quantity of images to be displayed.
You can use any kind of RSS feed, but they must contain thumbnails (the plugin will check for, in that order, media:thumbnail tags, or enclosure tags, or, if none of these are found, an img tag inside the feed item description). If you don’t undestand a word of this, just make sure your feed carries thumbnails, otherwise all you’ll see is a “No thumbnail found” text…
You can also use this plugin from your theme templates, to display images lists anywhere else on your blog and you can easily give them a fixed size or a maximum size with CSS styling.

Image Feed Widget

A widget to display imges from RSS feeds such as twitter, flickr or youtube

danikoo

NEW: 
1. added – option to choose multiple post types, example: ?call_custom_simple_rss=1&csrp_post_type=page,post 
2. added – option to choose multiple post status, example: ?call_custom_simple_rss=1&csrp_post_status=publish,draft 
3. added – better documentation (tutorial).
A plugin to create a your own Custom Simple RSS Feed 
according to parameters you choose!
*** the best solution for using MailChimp RSS campaigns ***
in simple words: 
Ever wanted an rss feed for just a specific Author and specific Category?
Or Even an rss feed for a specific Custom Field ???
Well… now you got it !
The plugin does not alter your default wordpress feeds – it enables you to display feeds on the fly via specific url with pre defined url query parameters.
for example:
display only 5 items from specific category order by name descending:
www.yordomain.com/?call_custom_simple_rss=1&csrp_posts_per_page=5 
&csrp_orderby=name&csrp_order=DESC&csrp_cat=4
Filter items by:
<ul>
<li>category id</li>
<li>post type</li>
<li>post status</li>
<li>tag</li>
<li>range of dates</li>
<li>and even meta keys and values!</li>
<li>NEW! filter by custom taxonomy</li>
</ul>
Order by:
<ul>
<li>name</li>
<li>date</li>
<li>author</li>
<li>ID</li>
<li>etc</li>
</ul>
More Features:
<ul>
<li>number of items to return</li>
<li>pagination </li>
<li>show post thumbnail or not?</li>
<li>set post thumbnails size to display?</li>
<li>show post custom fields (espically usefull if your using your rss as an affliate feed)</li>
<li>filter by date published or modified</li>
</ul>

Custom Simple Rss

A plugin to create your own Custom Simple RSS Feed according to parameters you choose

Image Feed Widget vs Custom Simple Rss