PressMaximum

This plugin will add Topbar Countdown on the top of your website that help you launch an offer or a promotions.
<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.

Lamansky

WordPress Tweaks is a powerful yet simple plugin to help you push the boundaries of WordPress by fine-tuning its many aspects. This multi-purpose plugin specializes in simple toggle-on/off changes and dropdown selections. It adds many useful settings pertaining to comments, posts, media, the administration back-end, and much more. Some tweaks can even replace plugins that you may already have installed.
The WordPress Tweaks plugin adds a “Tweaks” page to your “Settings” menu. Each individual tweak can be enabled/disabled at will using a checkbox or dropdown. An instant search bar makes it a snap to find the tweak you’re looking for.
The tweaks are as follows:
<ul>
<li>Admin
<ul>
<li>Disable the admin bar on the front-end</li>
<li>Disable the Dashboard</li>
<li>Disable tag autocomplete</li>
<li>Disable WordPress’s admin footer text/links</li>
</ul>
</li>
<li>Comments and Pings
<ul>
<li>Disable self-pinging</li>
<li>Dofollow comment author links</li>
<li>Dofollow comment body links</li>
<li>Open external comment links in new windows</li>
</ul>
</li>
<li>Media
<ul>
<li>Default media inserter tab (options: From Computer, From URL, Gallery, Media Library)</li>
<li>JPEG Quality</li>
</ul>
</li>
<li>Multisite
<ul>
<li>Let site admins edit the “Update Services” list</li>
</ul>
</li>
<li>Posts
<ul>
<li>Disable post revisions</li>
<li>Force excerpts on archives</li>
<li>Open external post links in new windows</li>
<li>Add a “Continue reading” link to excerpts</li>
</ul>
</li>
<li>Updates
<ul>
<li>Core update auto-installation (options: disabled, minor only, major and minor)</li>
</ul>
</li>
</ul>
<a href="https://downloads.wordpress.org/plugin/wordpress-tweaks.zip" rel="nofollow ugc">Download it now</a> and begin tweaking!
Supported Languages: English, Spanish, and Polish

WordPress Tweaks

Adds many must-have options for tweaking comments, posts, media, multisite, the administration back-end, and more.

Topbar Countdown vs WordPress Tweaks