Animelon is a website that displays the subtitles over japanese anime but the trick is that you can click on the subtitle. The video will pause automatically and a translation of the word will come up. So you can very quickly and interactively learn japanese.

I don’t think I’m far enough yet to make this useful, I have to click on probably 80-90% of the words and my time is probably better spent on anki vocab from japanese class or at wanikani for kanji. But once I feel more comfortable with my vocabulary and sentence structure this is a tool I think could be really useful.