I hate browser plugins - but this needs to be a browser plugin. Then I would use it while reading HN. ;-)
I would suggest tackling dynamic difficulty and algorithmic selection of what words to learn, when, and how often, and then let improving LLMs handle accuracy improvements.
Just tried Toucan and it can't be disabled on localhost, a major pain for using it during work as an engineer. For those that haven't used toucan, it's an extension that translates words/phrases inline on a page with various levels of replacement frequency and complexity based on your proficiency with the language.
Nice idea - although I hate having to start from scratch and having to "train" the system to know my level and vocabulary. I think it's a bummer that it's not common to be be able to exchange vocabulary lists between apps.
That would be amazing, not everyone reads eBooks (whether because they don't read books, or just prefer physical) but everyone whose a potential user anyway does browse websites.
Also because while I absolutely love the idea for seamless Hinglish style integration (as opposed to say a side bar which just told you what some words would be in a different language) it does mean that I'm no longer really reading the book, I'm reading the content but not the author. I don't personally read anything that I'd want to alter like that, but I can imagine for others it might limit its use to 'trashy novella read while travelling' or something.
Tldr the idea is brilliant, but for me too it needs to not be for eBooks.
I would suggest tackling dynamic difficulty and algorithmic selection of what words to learn, when, and how often, and then let improving LLMs handle accuracy improvements.