But, I would like to see some more about what it offers. Right now it looks like it is a video caption replacer with a dictionary. There are free tools like that that exist. Anki is a plugin and not built in, why? What about those starting learning? Do you have lessons or small references?
What's your plan for ML? Honestly, the largest benefit I see is for pronunciation feedback. This is a thing a lot of apps get wrong, because it is important to learn how to pronounce things from the beginning. This usually isn't as big of a problem for someone learning English but tones are a bit more important in Korean though not as much as say Chinese (this is part of why it's typically easier to understand someone in English with a very heavy accent than understanding Chinese with a very heavy accent). But a self learner is going to have an incredibly difficult time getting verbal feedback while a native or more traditional learner has this feature built in because there's another person there to give them feedback.