I think this as a useful tool

genial una app genial

Pas possible de choisir le français par défaut à la place de l'espagnol.

請ADD zh-TW 繁體中文語系

It does exactly what it claims to do.
Whilst I would prefer to have a full page translation, this is simpler than copying and pasting a selection into a new web page - this extension does all the repetitive work for you.

Easy to use, make its job.