Modeewine

<h4>What is «Polylang Theme Strings» and what for is it?</h4>
This plugin gives additional features to the plugin Polylang. It automatically scans all templates files and scripts of the active WP theme (and all plugins) for available strings that can be translated. For example:
<ul>
<li><code>pll__('...');</code></li>
<li><code>pll_e('...');</code></li>
</ul>
and adds them to the Polylang registery, after what you can manage the translation of finded strings using the administration panel. It will make your life easier for the development of multilanguage’s projects, because you will not need to enter the needed strings to translate manually – the plugin will do all the work for you. 
Don’t forget that in the example are described the PHP-function calls, that is why they have to be inside of PHP-tags.
<h4>How works «Polylang Theme Strings»?</h4>
You have to install the plugins «Polylang» and «Polylang Theme Strings» on your multilanguage WordPress CMS project and they must be both active. When you are in the settings of plugin (Polylang) in the tab «Strings translation» the «Polylang Theme Strings» scans automatically the active theme of your project, find all the code strings that needed to be translated, adds them to the register, displays them on that page and gives to user the ability to translate these strings.
Like you can see, the «Polylang Theme Strings» is perfectly integrate with the «Polylang» plugin and works in automatically mode – it is comfortable, simple, and useful!
From version 4.0 «Polylang Theme Strings» got settings page where you can configure the search strings-translations more deeply.
Learn more in <a href="http://modeewine.com/en-polylang-theme-strings" rel="nofollow ugc">http://modeewine.com/en-polylang-theme-strings</a>.

Polylang Theme Strings

I think there is a bug and it is changing the site language to english.

Works fine

Automatic scanning of strings translation in the theme and registration of them in Polylang plugin. Extension for Polylang plugin.

JS Morisset

Meta (Facebook and Instagram) Commerce Manager Catalog Feed XMLs for WooCommerce and custom product pages.
E-Commerce Plugin Optional:
WooCommerce is suggested but not required – the WPSSO Commerce Manager Catalog Feed XML add-on can also use product information from custom product pages.
Complete WooCommerce Support:
WooCommerce simple products, product variations, product attributes, product meta data, and custom fields are all fully supported.

Automatic Multilingual Support:
The Meta (Facebook and Instagram) product catalog feed XMLs are automatically created in your site’s language(s) from Polylang, qTranslate-XT, WPML, or the installed WordPress languages.
After activating the WPSSO Commerce Manager Catalog Feed XML add-on, see the SSO > Facebook Commerce Manager settings page for your feed URLs.
Meta (Facebook and Instagram) Commerce Manager Catalog Feed XML Attributes:
<ul>
<li>Additional image link <code>&#91;additional_image_link&#93;</code></li>
<li>Age group <code>&#91;age_group&#93;</code></li>
<li>Availability <code>&#91;availability&#93;</code></li>
<li>Brand <code>&#91;brand&#93;</code> (inluding MPN, UPC, EAN, and ISBN)</li>
<li>Condition <code>&#91;condition&#93;</code></li>
<li>Color <code>&#91;color&#93;</code></li>
<li>Description <code>&#91;description&#93;</code></li>
<li>Gender <code>&#91;gender&#93;</code></li>
<li>Google product category <code>&#91;google_product_category&#93;</code></li>
<li>ID <code>&#91;id&#93;</code></li>
<li>Image link <code>&#91;image_link&#93;</code></li>
<li>Item group ID <code>&#91;item_group_id&#93;</code></li>
<li>Link <code>&#91;link&#93;</code></li>
<li>Material <code>&#91;material&#93;</code></li>
<li>Pattern <code>&#91;pattern&#93;</code></li>
<li>Price <code>&#91;price&#93;</code></li>
<li>Sale price <code>&#91;sale_price&#93;</code></li>
<li>Sale price effective date <code>&#91;sale_price_effective_date&#93;</code></li>
<li>Shipping weight <code>&#91;shipping_weight&#93;</code></li>
<li>Size <code>&#91;size&#93;</code></li>
<li>Title <code>&#91;title&#93;</code></li>
</ul>
<h3>WPSSO Core Required</h3>
WPSSO Commerce Manager Catalog Feed XML is an add-on for the <a href="https://wordpress.org/plugins/wpsso/" rel="ugc">WPSSO Core plugin</a>, which creates extensive and complete structured data to present your content at its best for social sites and search results – no matter how URLs are shared, reshared, messaged, posted, embedded, or crawled.

WPSSO Commerce Manager Catalog Feed XML

Meta (Facebook and Instagram) Commerce Manager Catalog Feed XMLs for WooCommerce and custom product pages.

Polylang Theme Strings vs WPSSO Commerce Manager Catalog Feed XML