PressMaximum

<p>This plugin will add Topbar Countdown on the top of your website that help you launch an offer or a promotions.</p>
<h3>Featured</h3>
<ul>
<li>2 Countdown type: Fixed timer for all visits and Start the countdown when first visits.</li>
<li>Custom page or post type to show.</li>
<li>Custom message.</li>
<li>Custom countdown box title.</li>
<li>Custom Input coupon box.</li>
<li>2 Countdown box title: Vertical and Horizontal.</li>
<li>Advanced color settings.</li>
</ul>


Topbar Countdown

Add a banner on the top of screen with countdown clock and custom message.

Blintux

<p>With this plugin you can turn on/off some theme and core services of WordPress or even you can customize it too.</p>
<h4>Frontend features</h4>
<ul>
<li>Remove generator meta tag</li>
<li>Remove RSD (Really Simple Discovery ) link</li>
<li>Remove Windows Live Writer link</li>
<li>Remove post relational links (prev, next)</li>
<li>Remove canonical link</li>
<li>Remove RSS feed links</li>
<li>Remove admin bar</li>
<li>Remove the Website URL field from the comment form</li>
<li>Remove allowed HTML tags text from the comment form</li>
<li>Quick maintenance</li>
<li>Force login</li>
<li>Open Graph meta tag generator</li>
</ul>
<h4>Backend features</h4>
<ul>
<li>Disable core (WordPress) update notification</li>
<li>Disable plugins update notification</li>
<li>Disable themes update notification</li>
<li>Hide login error messages</li>
<li>Define custom login error message</li>
<li>Enable “All Settings” item in Settings menu</li>
<li>Enable Link Manager feature</li>
<li>Enable Featured image support</li>
<li>Enable excerpt field for pages</li>
<li>Enable TinyMCE Editor for excerpt</li>
<li>Enable categories for pages</li>
<li>Display IDs in post/page list</li>
<li>Customize WP Mail</li>
<li>Remove WordPress version from footer</li>
</ul>
<h4>System information</h4>
<ul>
<li>Server time</li>
<li>Memory usage</li>
<li>SQL Queries</li>
<li>Post revisions</li>
<li>Disc usage</li>
</ul>
<h3>Arbitrary section 1</h3>


WP Caregiver

Adds many options for tweaking frontend and backend of your WordPress site.

Topbar Countdown vs WP Caregiver