EDD replace $0.00 with Free

file.php

<?php // DO NOT COPY THIS LINE

function jp_filter_edd_price( $formatted_price, $download_id, $price, $price_id ) {
	if( ! edd_has_variable_prices( $download_id ) && 0 == $price ) {
		$formatted_price = '<span class="edd_price" id="edd_price_' . $download_id . '">Free</span>';
	}
	return $formatted_price;
}
add_filter( 'edd_download_price_after_html', 'jp_filter_edd_price', 10, 4 );