Josh

This plugin will allow you to add a custom welcome message to your login/register screens. It will also allow you to add a separate custom message for your logout screen. The admin page allows you to add HTML code into the message boxes, so you can include images, links, videos, or any other HTML code. The options are only limited by your imagination. Check out the screenshots for an example.
Features:
<ul>
<li>Add a custom welcome message to all users who visit your login/register page.</li>
<li>Add a separate custom message to your logout page.</li>
<li>Change the default wordpress logo to your own custom image.</li>
<li>Change the default hover text from “Powered by WordPress” to your own custom message.</li>
<li>Change the default logo link from “www.wordpress.org” to your own custom link.</li>
<li>Manipulate the CSS for the message boxes to make beautiful effects and custom styles.</li>
<li>Add links, images, videos, embeds, iframes, or any other HTML compliant tags.</li>
</ul>
Support: 
<a href="http://forum.joshlobe.com/member.php?action=register&referrer=1" rel="nofollow ugc">Visit my support forum.</a> 
<a href="http://www.joshlobe.com/2012/01/wordpress-custom-welcome-messages/" rel="nofollow ugc">Visit my personal blog page for this plugin.</a>
Other Plugins by Me: 
<a href="https://wordpress.org/extend/plugins/ultimate-tinymce/" rel="ugc">Ultimate TinyMCE</a> – Finally unlock the true power of your visual editor.
<h3>Features</h3>
<ul>
<li>Add a custom welcome message to all users who visit your login/register page.</li>
<li>Add a separate custom message to your logout page.</li>
<li>Change the default wordpress logo to your own custom image.</li>
<li>Change the default hover text from “Powered by WordPress” to your own custom message.</li>
<li>Change the default logo link from “www.wordpress.org” to your own custom link.</li>
<li>Manipulate the CSS for the message boxes to make beautiful effects and custom styles.</li>
<li>Add links, images, videos, embeds, iframes, or any other HTML compliant tags.</li>
</ul>

Custom Welcome Messages

This plugin will allow you to add a custom welcome message to your login/register screens.  It will also allow you to add a separate custom message fo …

Yash Binani

This plugin can be used for Greeting your website users with different messages and images depending on Time of the Day.
As an administrator of the website you can adjust Time Settings for Morning,Afternoon,Evening and Night in (0-23) hour clock format.(1 means 1 AM and 13 means 1 PM).With these time settings You can write messages that you wish to display during that time.You can also give link of the images that you wish to display during that time duration.This plugin is widgetized so you can drag it to the side bar and you can display it in whichever position you want on your website.For managing all this a very simple and clean interface is given.
I am sure you will find it very easy and useful.
?
?

Time Based Greeting

Anytime greeting is ready for your website user. Time Based Greeting

Custom Welcome Messages vs Time Based Greeting