mcmwebsol

Protects uploaded files so they can only be viewed by logged-in users
This plugin does not work with the media library. It only protects files uploaded through the plugin itself.
Requires a web server that supports .htaccess files for access control, such as Apache on Linux. Please note that even Apache on Linux 
disables .htaccess files in newer versions in some configurations, so please check to make sure your files aren’t publicly accessible. 
You can test that your files are protected by using the wp-content/uploads/ path or 
 by using the “Test link security” link on the “List all protected uploads” page. You should receive a 403 Forbidden error 
 if it’s working correctly.
This plugin does not collect any private data itself though it’s possible logged-in users may upload private data to your website using this plugin.
PRO SUPPORT 
While we attempt to provide basic support for this plugin here on the WordPress.org forums, for advanced or priority support please use the pro version. 
The <a href="https://www.mcmwebsite.com/mcm-protected-file-view-pro/" rel="nofollow ugc">pro version</a> also adds per user role file permissions, so, for instance, you can have a file that’s only accessible to a premium role, while not accessible to a basic role.

MCM Protected File View

Protects uploaded files so they can only be viewed by logged-in users

eugenealegiojo

The plugin that will let admin user to add download links to any posts/pages in simplest way and hassle free. 
Allows all your site visitors to download any files from your website without any user restriction.
<h4>Features</h4>
<ul>
<li>Downloader button is available in your admin content editor for post, page or post type. Shortcode will be generated automatically.</li>
<li>Insert download links manually via shortcode [media-downloader] to any posts, pages or custom post types. Check for more parameters below (Embedding).</li>
<li>Allow users to directly download in all file formats for free.</li>
<li>No file size limit for downloads. 
For more information please check the <a href="http://phplugins.softanalyzer.com/simple-file-downloader/" rel="nofollow ugc">Simple File Downloader</a> documentation page</li>
</ul>
<h4>Embedding / generated Shortcodes</h4>
Create a new post/page and click the ‘Add Download’ button from the content editor, then generate the shortcode below:
<pre><code>[media-downloader media_id="9" texts="Download Now!"]
</code></pre>
Media id is automatically added from your media library.
Here are the all the available parameters when generating shortcode for file download:
texts
If you choose to leave the texts parameter empty, then it be defaulted to ‘Download File’.
image_url
You can also use image/button as your download link. If you supplied this parameter, then texts parameter will be replaced by this image.
<pre><code>[media-downloader media_id="9" image_url="http://domain.com/wp-content/themes/images/button.png"]
</code></pre>
class
You can add class to your download link either a texts or image button. This is useful if you want to apply your own style.
<pre><code>[media-downloader media_id="9" texts="Download PDF" class="download-pdf"]
</code></pre>
display_filesize
You also have an option to display the size of the file. Just set it to ‘yes’
<pre><code>[media-downloader media_id="9" texts="Download PDF" display_filesize="yes"]
</code></pre>

Simple File Downloader

Simplest way to add download links into your posts/pages.

MCM Protected File View vs Simple File Downloader