Maciej Molenda

With this plugin, you can mark the content of posts, pages or other products as visible only to users who have purchased the selected product or its variants.
Major features in Restricted content based on purchase include:
<ul>
<li>All content can be hidden in a specific post, page or product options or part of it can be hidden with a shortcode.</li>
<li>You can set a default text to appear in place of restricted content.</li>
<li>A custom or automatically generated excerpt with a fade out effect may also be shown in place of the restricted content.</li>
<li>You can set up redirection so that the user who have not purchased the indicated product cannot enter the post and will be redirected to another page.</li>
<li>WooCommerce is needed for the plugin to work.</li>
</ul>
The plugin is a simple solution for websites offering paid content such as online magazines, courses, etc., that do not need an extensive system with many features, but instead need the ability to limit the visibility of the content based on the purchase of the product.
Includes the following translations:
<ul>
<li>Polish (pl_PL)</li>
</ul>

Restricted content based on purchase

awesome plugin

Restricted content for users who have not purchased the indicated product or product variant.

squiter

This plugin create a button in your WordPress editor to set some parts of your posts as spoilers. 
These parts show a blocked content to your visitors, then must click in these blocks to show the original content.
<h4>Translators</h4>
<ul>
<li>Brazilian (pt_BR) – <a href="http://brunno.me/spoiler-block" rel="nofollow ugc">Brunno dos Santos</a></li>
<li>Romanian (ro) – <a href="http://webhostinggeeks.com" rel="nofollow ugc">Alexander Ovsov</a></li>
</ul>

Restricted content based on purchase vs Spoiler Block