Soflyy

<h4>Market your content virally on social networks by forcing users to perform a social action before accessing your protected content.</h4>
Check out the 2 minute demo video on YouTube: http://www.youtube.com/watch?v=aheR3_ROt94
Like To Keep Reading is a WordPress plugin that forces visitors to Like you on Facebook to access content on your website.
You can protect entire pages or posts, or just sections of pages or posts (our favorite) – i.e. your visitors can read the first two paragraphs and then must click the Like button to keep reading.
You can force visitors to Like your website homepage, any sub-page/URL on your website, or your Facebook page.
Like To Keep Reading also has optional Google+ and Twitter integration – so instead of Facebook Likes you can get Google +1s and Tweets from your visitors in exchange for access to your content.

Like To Keep Reading

Get more Facebook Likes, Google +1s, and Tweets by forcing users to perform a social action before accessing the rest of your content.

Abolfazl Sabagh

rng-refresh Plugin adds the meta box in edit post screen of the admin panel also you can add time period with template <code>Hour:Minutes:Seconds</code> of force refresh using it.
Main features in rng-ajaxlike include:
<ul>
<li>Very light and easy to use.</li>
<li>This plugin avoids from any conflict with other plugins.</li>
<li>has not any overhead.</li>
<li>Has a settings in order to determine post types that can have refresh meta box.</li>
</ul>
it is strongly was recommended that after the plugin is activated, go to the <code>Settings > Refresh Settings</code> and configure plugin.

rng-refresh

WordPress Plugin that refreshes the single template of public post types with a synchronism time period.

Like To Keep Reading vs rng-refresh