Translations

quickfix until developer adds this to the plugin himself:
Add the following to index.php:

function load_textdomain_for_woocommerce_pdf_invoices() {
	load_plugin_textdomain( 'woocommerce-pdf-invoices', false, dirname( plugin_basename( __FILE__ ) ) . '/lang/' );
}
add_action('init', 'load_textdomain_for_woocommerce_pdf_invoices');

and download the po file from:
http://www.bonusboek.nl/woocommerce-pdf-invoices.po

upload your translation to woocommerce-pdf-invoices-fr_FR.mo into
/wp-content/plugins/woocommerce-pdf-invoices/lang/

(Manually create this directory first!!)