It lets your international visitors translate English words using double click.
Vocabla helps people translate, collect & memorize words.
For Vocabla users, this button helps them collect the words they want to memorize without abandoning your website. For the rest of curious people, it's redirection to Vocabla page, so they can sign up free and go back to your site to translate & collect more words.
It's a win-win situation: - your international users more likely return to a different-language-friendly place - your website. - users who wants something extra - collect English words, can do that without leaving your page. Just while they are reading.