Adds a "Continue Shopping" button to the left of the Update/Save Cart buttons on checkout.
<?php
/*
 * Plugin Name: Easy Digital Downloads - Continue Shopping Button
 * Description: Adds a "Continue Shopping" button to the left of the Update/Save Cart buttons on checkout.
 * Author: Chris Klosowski
 * Author URI: https://easydigitaldownloads.com/
 * Version: 1.0
 */

add_action( 'edd_cart_footer_buttons', 'ck_edd_continue_shopping_button', 1 );
function ck_edd_continue_shopping_button() {
	$color = edd_get_option( 'checkout_color', 'green' );
	$color = ( $color == 'inherit' ) ? '' : $color;
?>
	<a href="<?php echo get_post_type_archive_link( 'download' ); ?>"><div class="edd-submit button<?php echo ' ' . $color; ?>"><?php _e( 'Continue Shopping', 'edd' ); ?></div></a>
<?php

}
To implement this snippet on your site, create a brand new, empty WordPress plugin and paste the above code inside.