Progressive Immersion от Aidan Welch

This extension is open-source and we do not track your data. BUT, it does send words selected to be translated directly to Google Translate, which can be a privacy risk. You should add websites you want the extension not to analyze to the exclusion list, or turn the extension off before visiting them. Be warned though that the extension starts to analyze a page when it starts to load so you should turn it off or add a page to the exclusion list before loading it.

View the source code or contribute here: https://github.com/AidanWelch/ProgressiveImmersion

And, sponsor the project here: https://github.com/sponsors/AidanWelch