WordPress: Show Current Theme Template
<?php if(current_user_can( 'manage_options' )): ?>
<!-- A little help for admin users + devs :) -->
<div style="position:fixed;width:100vw;color:#fff;background-color:rgba(0,0,0,.8);z-index:1000;bottom:0;padding:1em;">Theme Template: <?php global $template; echo basename($template); ?></div>
<?php endif; ?>