AxTongue

AxTongue is a website/app that hosts user-submitted "cross captions" for YouTube videos. This extension allows you to see those captions on the YouTube website. Cross captions are designed to let you understand a language you don't speak in real time. You can immerse yourself right away, without knowing a single word. The AxTongue website/app has many features that are not available with this extension, including a system for generating cross captions with AI, and a sophisticated flashcard-like system that integrates into videos. And there are many other features. However, the basic concept everything else revolves around, viewing cross captions, is fully available in this extension.

Screenshots from Chrome Web Store