Fahien

Since I started my personal blog, I began to wonder what would be the right way to internationalize it. Some people opt to create a dedicated site for each language and some people develop more sophisticated solutions. I made something quite simple: Flag Me.
<a href="http://www.fahien.me/flag-me" rel="nofollow ugc">Flag Me</a> is a WordPress Plugin which enables you to add a country flag before the title of your posts or pages in the sidebar. This makes it easier for visitors to understand the language in which it is written content.
<blockquote>
If you like the plugin, feel free to support my work <a href="http://www.fahien.me/donate" rel="nofollow ugc">donating via PayPal</a>.
</blockquote>

Flag Me

Flag Me enables you to add a country flag before the title of your posts or pages.

comotive

Supertext

msebel

This plugin allows the user to send a WordPress post or page to Supertext for translation or proofreading.
Process for translation
Supertext can translate content, titles, excerpts, image captions, shortcode arguments and custom fields. Simply order a translation instead of creating a new page. 
You will be presented with services, prices and deadlines. Select the right one for you. 
Once completed, the translation will be automatically inserted into a new page or post in your WordPress installation. 
You’ll be notified by email once your translated content has been uploaded to your website. 
This works for every post type that is translatable by Polylang or WPML.
Process for proofreading
For proofreading your existing page or post, select the option “order proofread”. You will be presented with services, prices and deadlines. 
Select the right one for you. Once completed, the proofread text will automatically be inserted into your post or page in your WordPress installation.
Please note
Translatable custom fields must be defined in the settings. Supported plugins at the moment are:
<ul>
<li>Advanced Custom Fields</li>
<li>Yoast SEO</li>
<li>All In One SEO pack</li>
</ul>
If the field is not available in one of the lists, you can define it by adding self defined custom fields.
The plugin supports following page builders:
<ul>
<li>Visual Composer</li>
<li>Beaver Builder</li>
<li>BE page builder</li>
<li>Divi page builder</li>
<li>SiteOrigin page builder</li>
<li>Elementor</li>
</ul>
We highly recommend to test the translation process for the page builders mentioned above and for any other that you may use.

Supertext Translation and Proofreading

This plugin allows you to order human translations for your pages and posts using Supertexts professional translation services.

Flag Me vs Supertext Translation and Proofreading