Phil

There are many uses for restricting content based on age, be it movie trailers, beer or other adult themes. This plugin allows you to set a restriction on what content can been seen or restricted based on the age of the user.
Features
<ul>
<li>Ask users to verify their age on page load</li>
<li>SEO Friendly – common bots and crawlers are omitted from age checks</li>
<li>Ability to add custom user agents for less common bots</li>
<li>Shortcode for in content restrictions</li>
<li>Choose to restrict an entire site, or selected content</li>
<li>Select a different age on individual content</li>
<li>Allow certain content to not be age gated under “all content” mode</li>
<li>Three choices for input; dropdowns, input fields or a simple yes/no button</li>
<li>Customise the order of the inputs based on your region (DD MM YYYY or MM DD YYYY)</li>
<li>Allow a “remember me” check box if desired</li>
<li>Ability to omit logged in users from being checked</li>
<li>Add your own logo</li>
<li>Update the text displayed on the entry form</li>
<li>Select background colour/image, foreground colour and text colour</li>
<li>Use built in styling out of the box, or your own custom style</li>
<li>Ability to add legal note or information to the bottom of the form</li>
<li>Redirect failed logins to a URL of your choice e.g. an alcohol awareness website.</li>
<li>Ability to use a non caching version</li>
<li>Various hooks to add even more customisation such as additional form fields</li>
<li>Compatible with multilingual plugins WPML, Polylang (2.3+), WP Multilang</li>
</ul>

Age Gate

the plugin does it's job properly, but it spams the dashboard with nags about next version age gate; you click dismiss and it's back there... very very annoying.

spamming dashboard with announcements

A plugin to check the age of a visitor before view site or specified content

Barry Carlyon

This Plugin allows Site Admins to easily configure and use the Adult Payment Gateway <a href="https://www.zombaio.com/" rel="nofollow ugc">Zombaio</a> for use with WordPress. In a more Secure and WordPress-y way that the existing recommended script.
Two ShortCodes help to make joining the site and displaying the Zombaio Site seal as easy as possible. 
As well as logging transmitted data from Zombaio as a Custom Post Type.
Currently only User Add, User Delete and User Rebill are Processed. 
But all data is logged.
In the future, Credit Purchase will be supported.
When a user delete/cancel occurs, the admin can choose whether the User is deleted from WordPress or just suspended from being able to login.
This plugin works with “Anyone can register” disabled, stopping users signing up without using a Zombaio based Join Form.
Built in Splash Page/redirection allows you to redirect logged out users to a WordPress Page of your Choosing, thus protecting your content from non members, as well as giving you the ability to warn users about the site content, or create a suitable “Join my Site” page. You can also choose pages that are unlocked/open to all users. For tours etc.
See <a href="https://wordpress.org/extend/plugins/wp-zombaio/other_notes/" rel="ugc">Other Notes</a> for Usage/Instructions
<h4>Help</h4>
For Extra help/support or otherwise, either use the <a href="https://wordpress.org/support/plugin/wp-zombaio" rel="ugc">WordPress Support Forum</a>, or <a href="http://barrycarlyon.co.uk/wordpress/contact/" rel="nofollow ugc">Drop Me a Line</a>
You can also reach out to us on <a href="https://twitter.com/wpzombaio" rel="nofollow ugc">Twitter</a>!
<h4>Whats Coming Soon</h4>
<ul>
<li>Credit Purchase and Spending there of</li>
<li>Flexible Protection</li>
<li>Suspend a User Manually</li>
</ul>
<h3>Usage</h3>
With the block enabled, only the landing page is accessable, and users are forced to login or register.
You can run with Anyone can Register turned off, which means users can only use your Landing page, or the Zombaio Join Form/Widget to Register.
You can refer to the in plugin guide, which contains lots of setup information, settings notes and advice.
The Plugin provides three Shortcodes which are also available as Sidebar Widgets.
The first being the Zombaio Site Seal, which you can enter in the settings and then quickly add it where needed.
[zombaio_seal]
ShortCode Arguments
<ul>
<li>align – save you having to wrap it in a div, you can use left, center or right to control page placement</li>
</ul>
The second being, the Join Form.
[zombaio_join]content[/zombaio_join]
ShortCode Arguments
<ul>
<li>join_url – the Zombaio Join URL for the relevant subscription</li>
<li>submit – the text to use on the Submit button</li>
<li>align – save you having to wrap it in a div, you can use left, center or right to control page placement</li>
<li>buttonalign – save you having to wrap it in a div, you can use left, center or right to button placement</li>
<li>width – the Form Width, just a number</li>
</ul>
ShortCode Content
The shortcode content is added to the form beneath the password field and the join button.
The third and final item is, a Login Form.
[zombaio_login]
Renders a login form, also available as a Widget

WP Zombaio

Catches Information from the Adult Payment Gateway Zombaio and acts accordingly

Age Gate vs WP Zombaio