Daiv Mowbray

This widget dynamically creates a list of posts from the active category. Displaying the first image and title in a scrolling list. It will display the first image in your post as a thumbnail,it looks first for an attached image, then an embedded image then if it finds the image, it grabs the thumbnail version. Oh, and by the way, it’s an animated vertical scroller, way cool. 
If the post has no image the widget uses a default image. This works best with the plugin Widget logic. Just set the widget to is_single() || is_category() and all your single viewed posts will have a scrolling thumbnail list of other posts in this category.
credits:
<ul>
<li>mootools – <a href="http://mootools.net/" title="Your favorite javascript framework" rel="nofollow ugc">Mootools</a></li>
<li>slideBox – <a href="http://www.mootools.nl/slideBox/" title="Riaan Los" rel="nofollow ugc">slideBox</a></li>
<li>Widget logic you will want this – <a href="https://wordpress.org/extend/plugins/widget-logic/" title="Widget logic " rel="ugc">Widget logic</a></li>
</ul>
Support
If you have any problems or suggestions regarding this plugin <a href="http://support.superslider.daivmowbray.com/forum" title="support forum" rel="nofollow ugc">please speak up</a>
Other Plugins 
Download These Plugins here:
<ul>
<li><a href="https://wordpress.org/extend/plugins/superslider/" title="SuperSlider" rel="ugc">SuperSlider</a></li>
<li><a href="https://wordpress.org/extend/plugins/superslider-show/" title="SuperSlider-Show" rel="ugc">SuperSlider-Show</a></li>
<li><a href="https://wordpress.org/extend/plugins/superslider-image/" title="SuperSlider-Image" rel="ugc">SuperSlider-Image</a></li>
</ul>
NOTICE
<ul>
<li>The downloaded folder’s name should be superslider-postsincat</li>
<li>Probably not compatible with plugins which use jquery. (not tested)</li>
</ul>
Features
<ul>
<li>pull images from posts in this category </li>
<li>animated scroller</li>
<li>Control max number of images.</li>
<li>Images link to post</li>
<li>control size of scroll area</li>
<li>Widget title is dynamic, writes category Name</li>
<li>works also for non attached images in your library</li>
<li>presents default image if none in post.</li>
<li>Uses WordPress native media / images</li>
<li>Control scroll speed</li>
<li>Control animation type</li>
</ul>
Demos
This plugin can be seen in use here:
<ul>
<li><a href="http://superslider.daivmowbray.com/wp-plugin-demos/superslider-postsincat/postsincat-elk" title="Demo" rel="nofollow ugc">Demo 1</a></li>
</ul>
<h3>USAGE</h3>
If you are not sure how this plugin works you may want to read the following.
<ul>
<li>First ensure that you have uploaded all of the plugin files into wp-content/plugins/superslider-postsincat folder.</li>
<li>Go to your WordPress admin panel and stop in to the widgets control page. Activate the SS Posts in Cat widget.</li>
<li>Configure the widget.</li>
<li>Go view a single post on the front side, you should see the superslider-postsincat widget in your side bar.</li>
<li>Optional: move the file postincat.css to your theme folder and the images inside of superslider-postincat/css/images to yourtheme/images, select “Load css from your theme folder” in the widget options panel. This will preserve any modifications you make to the css or image files, if and when there is a plugin update.</li>
<li>Recommended : The css is set up for thumbnails of 150 x 150 pixels, to display 3 images at a time with the default css set the widget height to 552. If you have your thumbnail sizes set differently in the WordPress admin, then you will need to adjust the css and the widget height accordingly.</li>
</ul>
<h3>OPTIONS AND CONFIGURATIONS</h3>
Available under > appearance > widget > SuperSlider-PostsinCat
<ul>
<li>theme css file to load or not (you may want to add the classes to your theme css and reduce file requests to the server).</li>
<li>widget title.</li>
<li>Add Category name to the widget title (this will change dynamically according to the active category).</li>
<li>number of images to pull from category.</li>
<li>height of display area.</li>
<li>Load css from your theme folder.</li>
</ul>
<h3>To Do</h3>
<ul>
<li>Add option to link images to a lightbox</li>
</ul>
<h3>Report Bugs Request / Options / Functions</h3>
<ul>
<li>Please use the support system at https://wordpress.org/</li>
<li>Or post to the wordpress forums</li>
</ul>
<h3>CAVEAT</h3>
Currently this plugin relies on Javascript to create the scroller. 
If a user’s browser doesn’t support javascript the scroller will display normally as a list of images.

Superslider-PostsinCat

This widget dynamically creates a list of posts from the active category. Displaying the first image and title in a scrolling list.

Marcin Pietrzak

Reading Position Indicator adds a stylish horizontal progress bar alongside your content, showing readers how far they’ve scrolled. It enhances user engagement by providing a clear visual cue of reading progress, ideal for blogs, articles, and long-form content.
Features 
* Horizontal progress bar displayed on posts and pages. 
* Customizable colors, opacity, rounded edges, and gradients. 
* Lightweight and performance optimized. 
* Easy setup with no coding required. 
* Translation ready. 
* Compatible with most WordPress themes.
Thank you <a href="http://pankajparashar.com/" rel="nofollow ugc">Pankaj Parashar</a> for your article on CSS-TRICKS about <a href="https://css-tricks.com/reading-position-indicator/" rel="nofollow ugc">Reading Position Indicator</a>

Reading Position Indicator

Add reading position indicator on page top.

Superslider-PostsinCat vs Reading Position Indicator