Suzanne

For Genesis child themes that output HTML5 only.
This plugin adds an entry field just below the title field on all post, 
page and custom post type edit screens. It allows you to specify a 
subtitle for the content and then outputs the result in an H2 tag just 
under the entry-title where you’d expect to find it.
This plugin is for use with Genesis HTML5 child themes only because it 
uses the hook, genesis_entry_header to position the output after the 
title but before the post-info.

Genesis Subtitles

For Genesis child themes that output HTML5 only.

Jory Hogeveen

This plugin adds a subtitle input field to all your widgets. You can also change the location of the subtitle and even use filters to change the subtitle output.
<h4>Filters</h4>
<ul>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/wiki#filter-widget_subtitles_element" rel="nofollow ugc"><code>widget_subtitles_element</code></a></li>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/wiki#filter-widget_subtitles_classes" rel="nofollow ugc"><code>widget_subtitles_classes</code></a></li>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/wiki#filter-widget_subtitles_default_location" rel="nofollow ugc"><code>widget_subtitles_default_location</code></a></li>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/wiki#filter-widget_subtitles_edit_location_capability" rel="nofollow ugc"><code>widget_subtitles_edit_location_capability</code></a></li>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/wiki#filter-widget_subtitles_available_locations" rel="nofollow ugc"><code>widget_subtitles_available_locations</code></a></li>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/wiki#filter-widget_subtitles_add_subtitle" rel="nofollow ugc"><code>widget_subtitles_add_subtitle</code></a></li>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/wiki#filter-widget_subtitle" rel="nofollow ugc"><code>widget_subtitle</code></a></li>
</ul>
You can use these filters inside your theme functions.php file or in a plugin. 
You can find me here:
<ul>
<li><a href="http://www.keraweb.nl/" title="Keraweb" rel="nofollow ugc">Keraweb</a></li>
<li><a href="https://github.com/JoryHogeveen/widget-subtitles/" rel="nofollow ugc">GitHub</a></li>
<li><a href="https://nl.linkedin.com/in/joryhogeveen" title="LinkedIn profile" rel="nofollow ugc">LinkedIn</a></li>
</ul>

Widget Subtitles

Great plugin. Love the developer-friendly filters.

Simple and useful

Add a customizable subtitle to your widgets

Genesis Subtitles vs Widget Subtitles