WP CHOOSE YOUR THEME, let to select an avaiable theme to your visitors. In your template, for example in sidebar.php, insert: <?php wp_chooseyourtheme(); ?> and a combo menu list shows the themes avaiable. When a your visitor click on item, the theme is changed.
For defautl all themes are shows. Use Admin configuration Appearance -> WP Choose Your Theme to hidden some themes.
Arguments
You can set args mode in:
COMBO MENU
<?php wp_chooseyourtheme(); ?> for combo menu or
<?php wp_chooseyourtheme("mode=menu"); ?>
<select class="wpcyt_combo">
<option>Theme name 1</option>
<option>Theme name 2</option>
<option>Theme name ...</option>
</select>
LIST
<?php wp_chooseyourtheme("mode=list"); ?> for list.
<ul class="wpcyt_list">
<li class="theme-name-1"><a href="..."><span>Theme name 1</span></a></li>
<li class="theme-name-2 selected"><a href="..."><span>Theme name 2</span></a></li>
<li class="theme-name-..."><a href="..."><span>Theme name ...</span></a></li>
</ul>
ROLL
<?php wp_chooseyourtheme("mode=roll"); ?> for roll.
<div class="wpcyt_roll">
<a class="next-theme" href="#"><span>Next Theme</span></a>
</div>