What is the difference from the original TWP? The original TWP - Translate Web Pages can not enable "Automatically translate when clicking on a link that takes you to the same domain as the current site" in Firefox Nightly for Android, but this custom version can. What can this extension do?

Your current page is translated without having to open new tabs.
It is possible to change the translation language.
You can select to automatically translate.
To change the translation engine just touch the Google Translate icon.

Why do you need to access your data on all the websites you visit? To translate any website it is necessary to access and modify the text of the web pages. And the extension can only do that, with that permission. How are the pages translated? The pages are translated using the Google or Yandex translation engine (you choose). And how's my privacy? We do not collect any information. However, to translate, the contents of the web pages will be sent to Google or Yandex servers. Limitations Some pages like support.mozilla.org and addons.mozilla.org will not be translated. For security reasons, the browser blocks extensions from accessing these sites.