This plugin allows you to write posts in more than one language, all you have to 
do is to add some divs to your posts, each div with a class, that is the 
language’s name. This way your readers will be able to just click in the flags 
and change between languages.

WPMultiLanguageChanger

This plugin allows you to write and you readers to change between languages in your blog in a easy way.

Ryuhei Yokokawa

Plugin will allow you to fetch the WP-API (WP-JSON-API) call with a “lang” variable. It will retrieve the right content from WPML/WP.
This only works with WPML and WP-API installed. I tested only with the latest version as of now: 
* WPML 3.1.9.6 
* WP REST API 1.2.1

WPML to WP API

Allows you to request a language with your WP-API and WPML site.

WPMultiLanguageChanger vs WPML to WP API