Boone Gorges

reblevins

Mariusooms

Requires BuddyPress 1.7+ and PHP 5.3+.
The BuddyPress Groupblog plugin extends the group functionality by enabling each group to have a single blog associated with it. Group members are automatically added to the blog and will have blog roles as set by the groupblog admin settings.
Features:
<ul>
<li>P2 integration and frontend posting.</li>
<li>Admin can set Template specific groupblogs.</li>
<li>Allow group admins choose the desired template page themselves.</li>
<li>Full blog theme integration. The included bp-groupblog theme mimics the group pages.</li>
<li>Automated blog registration at group creation stage.</li>
<li>Bypass default blog validation to allow dashes, underscores, numeral only and minimum character count.</li>
<li>Blog privacy settings are initially inherited from group privacy settings.</li>
<li>Group members are automatically added to the blog.</li>
<li>Blog roles match group roles as set by the group admin.</li>
<li>Solid error checking that the blog follows validation.</li>
<li>Group admin tab to access the group-blog settings.</li>
<li>Blog themes will have the ability to pull in group info and create a theme that could resemble the group exactly.</li>
<li>Leaving the group will downgrade the member role to ‘subscriber’.</li>
<li>Allow the group admin to select one of his/her existing blogs.</li>
<li>A new ajax backend.</li>
</ul>

BuddyPress Groupblog

BuddyPress Groupblog extends the group functionality by enabling the group to have a single blog associated with it.

itthinx

The plugin protects a site so that only members can access its pages.
Suitable for site lockdowns, private sites and sites that are under construction.
It allows to redirect visitors to a particular page or to the WordPress login.
Members who are logged in have access to the site. 
Members must belong to the site’s Registered group, or to a particular group as determined specifically for the site.
The plugin is an extension to <a href="https://wordpress.org/plugins/groups/" rel="ugc">Groups</a> which is required.
The redirection settings can be adjusted in Settings > Groups Blog Protect :
Redirection options can be set for the blog – or for each blog in a multisite setup:
<ul>
<li>no redirection</li>
<li>redirect to a specific post, note that with this option the blog is shown to the visitor but only that page can be visited</li>
<li>redirect to the WordPress login</li>
</ul>
The redirect status code can be selected among:
<ul>
<li>Moved Permanently (301)</li>
<li>Found (302)</li>
<li>See other (303)</li>
<li>Temporary Redirect (307)</li>
</ul>
Site administrators can determine which group is used to protect the site:
<ul>
<li>By default, users must belong to the Registered group to be able to access the site, so any registered user who is logged in will have access.</li>
<li>The constant <code>GROUPS_BLOG_PROTECT_GROUP</code> can be set in <code>wp-config.php</code> to indicate the name of the group to which users must belong to be able to access the site.</li>
<li>For multisites, the <code>GROUPS_BLOG_PROTECT_GROUP_n</code> constant can be used to indicate the name of the group required to access a particular site, where <code>n</code> is the blog ID of the site.</li>
</ul>

Groups Blog Protect

Protect access to blogs via group memberships powered by Groups.

BuddyPress Groupblog vs Groups Blog Protect