JS Morisset

Add a user locale drop-down menu item in the WordPress admin back-end admin and front-end toolbar menus.
Perfect for anyone that needs to switch languages quickly and easily – allows logged-in users to change their preferred locale / language setting right from the toolbar menu (instead of having to update their WordPress user profile page).
The default WordPress behavior is to apply the user locale preference to the admin back-end only – this plugin extends the user locale / language preference to the front-end webpage as well.
There are no plugin settings – simply install and activate the plugin.
<h4>Do you use the Polylang plugin?</h4>
If the Polylang plugin is active, the user locale menu will automatically use the correct Polylang language URLs for the current webpage.

JSM User Locale Selector

Hi, I think this plugin is really useful, stable and reliable.
I've been recommending it in the BuddyPress forum and also now in my own translation helper plugin which I designed to work with this: [link removed]
So excellent, 5 stars.

Really useful

A simple but effective plugin. The convenience of a quick admin language switcher saves precious seconds. Thanks.

Effective

Add a quick and easy user locale / language selector in the WordPress admin back-end and front-end toolbar menus.

jomo

Adds Translate button to the WordPress admin bar to translate any selected text. 
Adds Translate buttons to BuddyPress and bbPress messages.
Translate translates selected text to current locale: where user is logged in, this is the user’s preferred language.
Perfect for a multilingual Buddypress site, this tool allows your users to translate messages to their own language.
Other tools translate the whole site but a polyglots and language learners may not want this, for learning it is best to see the original, and translate only where necessary. 
Or the whole site may be already translated to your preferred language but you are getting messages from other users (or from some untranslated plugin) and you want to translate those.
Currently uses Google Translate.
<h3>Contribution</h3>
If you have a feature request, or if you have developed the feature already, please feel free to use the <a href="https://github.com/Jon007/jm-buddy-translate/issues" rel="nofollow ugc">Issues</a> and/or (Pull Requests)[https://github.com/Jon007/jm-buddy-translate/pulls] section.
Plugin translations are provided for English, French, Spanish, Chinese, please feel to contribute more <a href="https://translate.wordpress.org/projects/wp-plugins/jm-buddy-translate" rel="nofollow ugc">translations</a>.

JM Buddy Translate

Quick and easy translate BuddyPress and bbPress messages or any selected text.

JSM User Locale Selector vs JM Buddy Translate