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

Prem Tiwari

A Flickr WordPress plugin to display user’s and group’s photos in sidebar widgets.
<a href="http://www.freewebmentor.com/2016/09/responsive-flickr-widget.html" rel="nofollow ugc">Plugin Documentation & Demo</a>
<h3>Features :</h3>
<ul>
<li>Responsive Design.</li>
<li>Easy to configure.</li>
<li>Change “Photo Type” user or group as you want.</li>
<li>You can sort by latest or randomly.</li>
<li>Compatible with all major device like iPhone, iPad, Tablets, PC.</li>
</ul>

Responsive Flicker Widget

A Flickr WordPress plugin to display user's and group's photos in sidebar widgets.

Recent photos widget vs Responsive Flicker Widget