Por lo poco que lo usé, funciona bien!!!

This is the most user friendly translation option I've found for Firefox Mobile. If you have a fork of Firefox Android (such as Mull), you can add this to a custom collection to use it on your phone. I usually leave it disabled and, when I need something translated, turn it on to show the translation bar at the bottom of the screen.

Firefox denildiği zaman akla gelen eklentilerden biri.Hiç düşünmeden yükleyin derim

Sometimes, "show original" function doesn't work.

I am so happy with this addon, it works really well.
Previously, I was using the translate addon that has the biggest number of users but it could not even translate Instagram pages that were in Russian. Using this addon, it is very easy to do that automatically for Instagram or any other sites.

Many thanks to the developer of this addon.

GOOD

Edit: It's fixed! Thank-you, Dev.

Newest update ruined this addon. It is unreadable because of transparency.

Всплывающее окно перевода стало довольно прозрачным, в некоторых ситуациях происходит каша так как сливаются слова из-за сильной прозрачности, что режет глаза. Да и цветовое решение не всем заходит судя по комментариям из других источников.
Было бы неплохо если бы в настройках стиля добавили возможность пользователю самому настраивать степень прозрачности и цветовую гамму.
И только из-за этого убрал две звезды, из ранних поставленных пять... ⭐⭐⭐
А так приложение великолепно.
P.S.
Вернулся на прошлую версию 9.4.2... вернул одну звезду.

P.S "Try version 9.5.1"
Вернул ⭐⭐⭐⭐⭐

Basically good and outstandingly convenience translation tool, which makes web pages readable in any language. However, suddenly pop-up translation window became quite annoying transparent one. I prefer the one shown in your screenshots. Is this an effect of Firefox update? I also prefer translation by deepL WITHOUT another tab opened, than transparent window. Thank you.