jtatum

Get Post adds a tag that allows you to retrieve and display the latest post 
identified by a specific set of parameters.
When this plugin is active, any post or page can contain the get-post markup 
as follows:
<pre><code>[get-post tag=some-tag]
</code></pre>
This will be replaced with the latest post tagged with the given tag.
<h4>Parameters</h4>
The parameters control which posts are retrieved by get-post. Options can be 
used in combination to build a list of criteria for post or posts to retrieve. 
By mixing criteria, you can exert a lot of control over the post(s) which are 
found by the plugin.
<pre><code>[get-post tag=some-tag random show=3]
</code></pre>
One note on WordPress in general: if you specify criteria that WordPress can’t 
match, it will make something up. For instance, if you specify a tag or 
category that doesn’t exist, it will simply retrieve the latest post with no 
indication that anything is wrong. Take care to ensure that the options you 
specify are what you intend.
Several of these parameters work best when specifying the slugs. For instance, 
when specifying a tag it’s best to use the slug value rather than the full 
name of the tag. To find the slug, see the admin panel -> posts -> post tags. 
The slug is listed right on that page.
You may wish to specify an option value with a space in it. This is 
accomplished with quotes:
<pre><code>[get-post option="a value with spaces"]
</code></pre>
<ul>
<li>
tag: 
Specify a tag to search for. The tag’s slug should be specified.
<pre><code>[get-post tag=some-tag]
</code></pre>
</li>
<li>
category: 
Specify a category to search for. The category’s slug should be specified.
<pre><code>[get-post category=some-category]
</code></pre>
</li>
<li>
show: 
Specify the number of posts to show.
<pre><code>[get-post show=5]
</code></pre>
</li>
<li>
template: 
Specify the template to use. This specification overrides the template set in 
the options panel of the admin interface. See the template section for more 
details on template tags. NOTE: If entering any HTML into this, please be 
sure to select the HTML editor rather than the visual editor.
<pre><code>[get-post template="<h1>Title: {title}</h1>"]
</code></pre>
</li>
<li>
random: 
Select a random post from the matching criteria
<pre><code>[get-post random]
</code></pre>
</li>
<li>
default: 
This isn’t really an option. By default, get-post displays the latest blog 
post.
<pre><code>[get-post]
</code></pre>
</li>
</ul>
<h4>Templates</h4>
Get-post ships with a default template that should render the usual post 
details in a form that fits well with most themes. You can customize this 
template to add or remove data from the included post. Additionally, you can 
use the <code>template</code> parameter to the <code>[get-post]</code> tag to specify a one-off 
template.
Using the <code>show</code> parameter will retrieve multiple posts. In this case, the 
template will be repeated one time for each retrieved post.
These tags are replaced with the value from the retrieved post. For instance, 
a template containing <code>{title}</code> will actually have the title of the retrieved 
post, rather than the word <code>title</code>.
<ul>
<li>
{title}: 
The title of the post.
</li>
<li>
{content}: 
The content of the post.
</li>
<li>
{author}: 
The author of the post.
</li>
<li>
{date}: 
The date the post was written.
</li>
<li>
{time}: 
The time the post was written.
</li>
<li>
{permalink}: 
A link to the post itself.
</li>
<li>
{authorlink}: 
A link to all posts by the post’s author.
</li>
<li>
{id}: 
The post’s ID number.
</li>
</ul>
<h4>Examples</h4>
Indicate when your blog was last updated:
<pre><code>Blog last updated [get-post template="{date} at {time}."]
</code></pre>
Link to the latest post:
<pre><code>Check out my post: [get-post template="<a href='{permalink}'>{title}</a>"]
</code></pre>
<h4>How it works</h4>
This plugin does something a little bit unorthodox: It reenters <a href="https://codex.wordpress.org/The_Loop" rel="nofollow ugc">“The 
Loop”</a> while the post content is being rendered. Then, it calls 
whatever WordPress internal functions will safely work, using raw data from 
$post when these functions are unsafe to call again. People curious about the 
internals should examine <code>class-get-post-getter.php</code>. The class is structured 
to be reusable by any other GPL2 projects.

Get Post

Get Post adds a tag that allows you to retrieve and display the latest post identified by a specific set of parameters.

samuelrajkumar

Giveaway Helper retrieves Emails and Names of the commentators of an article (especially giveaway article). You can easily select all those Emails or Names, copy them and paste them into Random.org to select winners.
Features:
<ul>
<li>Retrieves the Emails and Names uniquely. Even though there are multiple entries of same person, only 1 entry is accepted.</li>
<li>Ability to filter-out any Email Addresses you want.</li>
</ul>

Giveaway Helper

Plugin that helps you select winners through Random.org

Get Post vs Giveaway Helper