rufein

Extension of the mqtranslate plugin that creates a widget that displays a language selector with language codes. For example, if you have got a site in 3 different 
languages (Deutsch, english, spanish), the widget will display: de | en | es
The plugin is compatible with Qtrasnlate Slug {qts}.
It also has got the following filters:
<ul>
<li>‘lang-code-selector-content’ => This filter allows alter the content of each idiom.</li>
</ul>
<h3>Arbitrary section</h3>

mqtranslate langcode widget selector

Plugin that creates a widget with a language switcher with language codes. It's compatible with qtranslate and mqtranslate plugin.

Soft79

Migrates WPML translations to qTranslate.
Compatible with: 
<a href="https://wordpress.org/plugins/qtranslate-x/" rel="ugc">qTranslate X</a>, 
<a href="https://wordpress.org/plugins/qtranslate-slug/" rel="ugc">qTranslate Slug</a>, 
<a href="https://wordpress.org/plugins/woocommerce-qtranslate-x" rel="ugc">WooCommerce & qTranslate-X</a> (best used in combination with qTranslate X) and 
<a href="https://wordpress.org/plugins/qtranslate-support-for-woocommerce/" rel="ugc">qTranslate support for WooCommerce</a>
Might be compatible with other qTranslate forks and helper-plugins as well, but not tested.
Goodbye WPML, Hello qTranslate!
Note: This plugin will save you a lot of work, but more configuration and tweaking might be necessary.

W2Q: WPML to qTranslate

Migrates WPML translations to qTranslate.

mqtranslate langcode widget selector vs W2Q: WPML to qTranslate