Ghyslain Drolet

Simple Login SC does just what it means
Simple Login SC does not mess with other plugins because it does just login or logout a user. Nothing more. Nothing less. 
It uses the core functions of WordPress thus not slowing down your site. No fancy stuff or hard settings. This is just a login plugin!
Using Simple Login SC is absolutely easy
Just type the shortcode where you want a login form to show. 
Use [sl_shortcode] shortcode to add a login form to a page, post or in a text/html widget. 
You can optionally set the labels for “username”, “password”, the submit button and/or the welcome message, the logout text. Just by adding text to the shortcode.
Usage
Example: [sl_shortcode username_label=”What is your name?” password_label=”Password Please!” button_text=”Let me in!” welcome_text=”Hello” logouttext=”Let’s go outside!”]
This is very useful if the language pack is not available in your language or if you have a multilangual site running WPML. 
If you do not set one or all of the optional text, the default text of WordPress and the plugin will be used.

Simple Login SC

Adds a simple login form via a shortcode and does not add any extraneous code to slow your website. It just uses the core functions of WordPress.

Danny van Kooten

ibericode

Harish Chouhan

This is an add-on plugin for <a href="https://wordpress.org/plugins/mailchimp-for-wp/" rel="ugc">MC4WP: Mailchimp for WordPress</a>, adding the following features:
<ul>
<li>Subscribe to a different Mailchimp audience for each of your site’s languages.</li>
<li>Set the subscriber’s language based on the current site language.</li>
</ul>
This plugin requires PHP 5.3 or higher.

MC4WP: WPML Integration

WPML integration for the Mailchimp for WordPress plugin.

Simple Login SC vs MC4WP: WPML Integration