Brandon

This plugin is now deprecated, please use WordPress Access Control for access to new features, such as restrict to members or non-members, restrict to certain roles and specify a redirect URL. This name didn’t suite the version 2.0.
https://wordpress.org/extend/plugins/wordpress-access-control/
This plugin allows you to mark a page as “Members Only”. Once this is done, the user must login to view the page. However, you can still add the page to the menu, and it will then ONLY show up if the user is authenticated. That way you can have more items for logged in members on your website.
This plugin is designed for people using WordPress as a CMS. It’s extremely easy to use. You install the plugin, and activate it. Whenever you create or edit a page there is a checkbox on the sidebar that allows you to mark that page as members only.
This plugin now fully supports wp_nav_menu and wp_page_menu for older sites, so it should be compatible with older versions of WordPress, as well as wp_list_pages for certain themes.
It automatically sets the walker class to the one we custom made so theme developers don’t need to do anything

Members Only Menu Plugin

This plugin allows you to mark a page as "Members Only" and still add it to menus (Only visible if logged in)

Blake Jones

A simple plugin to add Google Tag Manager to your site.
<h3>External Services</h3>
Google Tag Manager
This plugin uses Google Tag Manager to manage and deploy marketing and analytics tags (such as tracking and analytics scripts) across your website.
<ul>
<li>What it is used for: Google Tag Manager helps in managing JavaScript and HTML tags used for tracking and analytics without having to modify the code after deployment.</li>
<li>What data is sent and when:
<ul>
<li>The plugin sends data to Google Tag Manager servers whenever a page or post is loaded on your site. </li>
<li>This includes:</li>
<li>Page URL: To identify which page is being viewed.</li>
<li>User interactions: Clicks, form submissions, or other events if set up in the Tag Manager.</li>
<li>Client ID: A unique identifier for tracking user sessions.</li>
<li>Data is sent automatically each time a page loads where the GTM script is included.</li>
</ul>
</li>
<li>Links to terms of service and privacy policy:
<ul>
<li><a href="https://marketingplatform.google.com/about/analytics/terms/us/" rel="nofollow ugc">Google Tag Manager Terms of Service</a></li>
<li><a href="https://policies.google.com/privacy" rel="nofollow ugc">Google Privacy Policy</a></li>
</ul>
</li>
</ul>
By using Google Tag Manager, you are also agreeing to allow Google to process data about your site visitors according to their privacy policies. Users should be aware that this might involve data collection across multiple websites for ad personalization, analytics, and other services provided by Google.

Only GTM

A simple plugin to add Google Tag Manager to your site.

Members Only Menu Plugin vs Only GTM