Scott Reilly

Even though you may add two spaces after each sentence when writing a post (assuming you subscribe to a writing style that suggests such spacing) web browsers will collapse consecutive blank spaces into a single space when viewed. This plugin adds a <code>&nbsp;</code> (non-breaking space) after sentence-ending punctuation to retain the appearance of your two-space intent.
NOTE: The plugin will only enforce the two-space gap in places where two or more spaces actually separate sentences in your posts. It will NOT insert a second space if only one space is present.
Links: <a href="http://coffee2code.com/wp-plugins/extra-sentence-space/" rel="nofollow ugc">Plugin Homepage</a> | <a href="https://wordpress.org/plugins/extra-sentence-space/" rel="ugc">Plugin Directory Page</a> | <a href="https://github.com/coffee2code/extra-sentence-space/" rel="nofollow ugc">GitHub</a> | <a href="http://coffee2code.com" rel="nofollow ugc">Author Homepage</a>
<h3>Hooks</h3>
The plugin is further customizable via two filters. Typically, these customizations would be put into your active theme’s functions.php file, or used by another plugin.
c2c_extra_sentence_space
The ‘c2c_extra_sentence_space’ filter allows you to use an alternative approach to safely invoke <code>c2c_extra_sentence_space()</code> in such a way that if the plugin were deactivated or deleted, then your calls to the function won’t cause errors in your site. This only applies if you use the function directly, which is not typical usage for most users.
Example:
Instead of:
<pre><code><?php echo c2c_extra_sentence_space( $mytext ); ?>
</code></pre>
Do:
<pre><code><?php echo apply_filters( 'c2c_extra_sentence_space', $mytext ); ?>
</code></pre>
c2c_extra_sentence_space_punctuation
The ‘c2c_extra_sentence_space_punctuation’ filter allows you to customize the punctuation, characters, and/or symbols after which double-spacing (when present) is preserved. By default these are ‘.!?’.
Arguments:
<ul>
<li>$punctuation (string): The default characters after which double-spacing should be preserved. Default is ‘.!?’.</li>
</ul>
Example:
<pre><code>/**
 * Modifies the list of characters after which two spaces should be preserved
 * to include a forward slash.
 *
 * @param string $punctuation The punctuation.
 * @return string
 */
function more_extra_space_punctuation( $punctuation ) {
 // Add the '/' and ')' characters to the list of characters
 return $punctuation . '/)';
}
add_filter( 'c2c_extra_sentence_space_punctuation', 'more_extra_space_punctuation' );
</code></pre>

Extra Sentence Space

Excellent

Force browsers to display two spaces (when present) between sentences.

Olav Kolbu

NASA makes a new Image Of The Day available every day in their gallery, 
complete with a fairly detailed description of what you see. This plugin 
grabs a thumbnail of the current image along with an extract of the 
accompanying description, and makes it available as a WordPress sidebar 
widget. Clicking on the thumbnail will take you to the NASA Gallery where 
you can view the full sized image and read the rest of the text. No 
local storage is used, the image and text is fetched on every view.
A friendly user let me know that the Image Of The Day is also 
available as an RSS feed. That greatly simplified this plugin and 
should make it impervious to cosmetic changes at NASA. In 
addition to this, the image width is now customizable. The height 
is calculated per image so that it stays proportional when scaled 
(down) to width.
<a href="https://downloads.wordpress.org/plugin/nasa-image-of-the-day.zip" rel="nofollow ugc">Download now!</a>
<a href="http://www.kolbu.com/2008/03/28/nasa-image-of-the-day-plugin/" rel="nofollow ugc">Support</a>

NASA Image Of The Day

Adds a sidebar widget to display the current image from the NASA Image Of The Day Gallery. Now using RSS.

Extra Sentence Space vs NASA Image Of The Day