stigcq

A plugin offering a widget showing recent photos in posts. It can be configured 
as for how many photos to show, the title on the widget and max width and height for 
thumbnails.
The thumbnails links to the post where the photo is showing. They show a mouse over 
effect with bigger version of the photo in a tooptip.
It has option to exclude photos from the view.
It has only been tested with WP 4.2, it might work with lower versions.

Recent photos widget

A simple widget which shows thumbnails of latest photos in posts

erikrasmussen

Javascript Flickr Badge uses pure javascript to place a Flickr badge in your widget-enabled sidebar to display recent photos. Photos 
may be filtered by tag if so desired. All communication with Flickr is client-side, so no extra load is placed on your server at all.
<a href="http://blog.jyst.us/javascript-flickr-badge?utm_source=Wordpress&utm_medium=Wordpress%2BPlugin%2BDirectory&utm_campaign=Javascript%2BFlickr%2BBadge" rel="nofollow ugc">Plugin Page</a>
<a href="http://www.youtube.com/watch?v=AyRj7U-dExI" rel="nofollow ugc">Demo Video</a>
<h4>Features</h4>
<ul>
<li>Customizable thumbnail size, number of rows, and number of columns to fit perfectly into any sidebar.</li>
<li>Works for your personal photo stream, group pools, or your friends photostreams.</li>
<li>Filtering by tag (user feed only).</li>
<li>Lightweight javascript. No heavy libraries required!</li>
<li>Works on mobile browsers</li>
<li>All the work happens client-side. No server load.</li>
<li>Animations, using CSS3: Vertical Scroll, Shuffle, Zoom (like Flickr’s Flash Badge), 3D Horizontal Flip, 3D Vertical Flip</li>
<li>Localized to Spanish.</li>
</ul>

Javascript Flickr Badge

Displays photos from Flickr, with optional tag filtering, with pure client-side javascript. Several eye-catching effects available.

Recent photos widget vs Javascript Flickr Badge