TL;DR: Works as intended, even on Firefox Quantum 57.0.4 (64-bit).

As the name implies; it's simple, and it translates, while a great majority of other translation add-ons DON'T.
More often than not they seem only capable of redirecting you to a Google Translate page containing whatever website or blog or piece of text you wanted to translate. Seriously, anyone with a computer and two hands could do that. And that's why this one stands out: it might not be spectacular or anything, but at least it's capable of translating whatever you highlight and does so in a neat little textbox, all without disrupting your workflow.

Even though the actual translations can be a bit rough from time to time, i'm usually able to make sense of it nonetheless.
So if you're looking for a simple and easy to use add-on for on-the-fly translation, this might be your best option.

-Simplicity in its best.
-Maybe you should consider a setting for translating only by selection.
-Sometimes translate button doesn't appear.

One of my favorite extensions hhha

Excellent add-on. Please add a translation by clicking the hotkey. Thank you!

After my favourite Translator addon "Google Translator" not working anymore, and the last update was early 2017, I thought it's about time to search for an alternative. And here i am.

It works just as advertised, but it lacks 2 big features :

a. "double click" to translate,really useful when you only want to translate one word, and
b. Google definition, when translating only one word in the same target language (ENG->ENG), just like in the good old "Google Translator" add-on.

Пока работает нормально. Были проблемы с дополнением для конвертации в dark backgroaund, но потом смог решить эту проблему.

best!

Hey bro, how do I contact you?

I tried various translators, but this is the best!

使い方がとてもシンプル。翻訳ウィンドウも見やすい。動作も非常に速い。良い。

This is a great and well designed translation add-on!

However:
- Automatic switching to second language seems to be not working when selecting text. (reported bug)
- Switching language in the popup box (after clicking the icon) would be good to remember at least till the end of browser session (or another change).
- Using the language (selected in the popup box) as "first" for the context menu action (at least till the end of browser session) would be a great feature.

And again: this is a great and well designed translation add-on!
(I will give 5 stars after fixing the above issues)

Nice Work!

Actually neat, useful and lightweight extension.

Elegant in its functional design and simplicity. I'd give this 10-stars if I could.

很方便的翻译工具，就不用搜索翻译了，哈哈哈

不错。但希望能支持一下快捷键操作。

I was looking because the one I was using was not updated to FF57.
I have seen his addon several times. And I did not realize it was the one I needed.
I think because the example images are not very enlightening. They are in Japanese.

So you need more pictures to explain the operation:
1 - Text selected in German, or Spanish, or French, with the button appearing.
2 - Box with the text translated in Japanese.
3 - Box with the text translated in English.
4 - Options with Japanese text.
5 - Options with English text.
6 - Toolbar box with Japanese text.
7 - Toolbar box with English text.

Add in Options the option "Traslate in New Tab".
A Near Tab. Not a Tab in the End.

Do not use the expression "Target language". I was confused.
Use the expression "Translate To". It's more clear.
The second language only works in the toolbar panel. It took me a while to realize.

Is the best.

Best translation add-on! Fast smart pop-up - that what I looked for!

翻译速度快，既可取词，也可以从工具栏折叠菜单中当小辞典直接输入翻译。棒！

Very ueful utility. Simple and effective. You've only to select the word or the phrase, to click on a little botton and you receive the translation in a pop-up. Simple but intelligent!