Translating Plugins

__.php

<?php $greeting = __( 'Hello There!', 'text-domain' ); ?>

_n.php

<?php
$messages = get_message_count();

// Simple form
$text = _n( 'You have one message', 'You have lots of messages', $messages, 'my-message-app' );

// Displaying the actual number
$text = sprintf( _n( 'You have one message', 'You %s messages', $messages, 'my-message-app' ), $messages )
?>

_x.php

_x( 'Pair', 'A pair of people', 'my-plugin-textomaind' );
_x( 'Pair', 'As in: pairing devices', 'my-plugin-textomaind' );

general-po.txt

#: path-to-file:line-number
msgid "string to translate"
msgstr "translation goes here"

js.js

jQuery.html( "<h2>" +  wma.section_title + "</h2>" );

js.php

add_action( 'admin_enqueue_scripts', 'motivation_assets' );
function motivation_assets($hook) {
    wp_enqueue_script( 'motivation-scripts', plugin_dir_url( __FILE__ ) . 'scripts' );
    wp_localize_script( 'motivation-scripts', 'wma', array(
    	'section_title' => __( "Today's motivation", 'wp-admin-motivation' )
    ));
}

load-textdomain.php

add_action('plugins_loaded', 'wan_load_textdomain');
function wan_load_textdomain() {
	load_plugin_textdomain( 'wp-admin-motivation', false, dirname( plugin_basename(__FILE__) ) . '/lang/' );
}

pofile.txt

msgid ""
msgstr ""
"Project-Id-Version: WP Admin Motivation 1.0.0\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2015-04-27 13:09+0100\n"
"PO-Revision-Date: 2015-04-27 13:09+0100\n"
"Last-Translator: Daniel Pataki <contact@tastique.org>\n"
"Language-Team: Daniel Pataki <hello@danielpataki.com>\n"
"Language: Hungarian\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"X-Poedit-KeywordsList: __;_e\n"
"X-Poedit-Basepath: .\n"
"X-Poedit-SearchPath-0: ..\n"

#: ../wp-admin-motivation.php:20
msgid "You are awesome"
msgstr ""

#: ../wp-admin-motivation.php:21
msgid "This website is boss"
msgstr ""

#: ../wp-admin-motivation.php:22
msgid "You look great today"
msgstr ""

#: ../wp-admin-motivation.php:23
msgid "Your earlobes are well rounded, good job!"
msgstr ""

style.css

#wp-admin-motivation {
	float: right;
	padding-right: 15px;
	padding-top: 7px;		
	margin: 0;
	font-size: 11px;
}

.rtl #wp-admin-motivation {
	float: left;
	padding-left: 15px;
}

translated-array.php

$motivation = array(
	__( 'You are awesome', 'wp-admin-motivation'),
	__( 'This website is boss', 'wp-admin-motivation'),
	__( 'You look great today', 'wp-admin-motivation'),
	__( 'Your earlobes are well rounded, good job!, 'wp-admin-motivation')'
);

wp-admin-motivation.php

<?php
/*
Plugin Name: Admin Motivation
Plugin URI: http://danielpataki.com
Description: Shows motivational messages in the admoin bar
Author: Daniel Pataki
Version: 1.0
Author URI: http://danielpataki.com
Text Domain: wp-admin-motivation
*/

function get_motivation_text() {

	$motivation = array(
		'You are awesome',
		'This website is boss',
		'You look great today',
		'Your earlobes are well rounded, good job!'
	);

	shuffle( $motivation );

	return $motivation[0];
}

add_action( 'admin_notices', 'show_motivation_text' );
function show_motivation_text() {
	$text = get_motivation_text();
	echo "<p id='wp-admin-motivation'>$text</p>";
}


add_action( 'admin_enqueue_scripts', 'motivation_assets' );
function motivation_assets($hook) {
    wp_enqueue_style( 'motivation-styles', plugin_dir_url( __FILE__ ) . 'styles.css' );
}

There’s a typo in translated-array.php: the single quote at the very end should be after

(…) good job!'