This is awesome. Should be the one "recommended".

Set a translate button on the toolbar,
I want to paste and translate the copied string instead of the selected string.
I can't do it with this add-on, so I use it together with Simple Translate.

La meilleure extension pour traduire des pages entière sur Firefox. (Après plusieurs essaies d'extensions.)

Excelente, Obrigado|Excellent thank you

Happy.

Amazing work! This was the only thing that made me keep on switching to chrome.

nb！！！！！！！！！！！！、

Phenomenal: open-source and works much better than every other translation add-on. One suggestion would be to disable the translate tooltip on selection by default, since there is already a context menu option to translate the current selection and the majority of selections made are not intended for translation. However, this is minor and can be disabled in settings.