I've recently been interested in Esperanto, and found a highly useful site for learning it. Lernu teaches you Esperanto by telling a story Esperanto with the English translation available by hovering over parts of the text, and with Esperanto sound available. It then asks you questions about the vocabulary and grammar in the text. I was wondering if there were any similar resources for learning Korean?
Glossing over words that you do not know while reading a text is what LingQ is all about. However, I have read that it does not do Korean well (https://www.reddit.com/r/Korean/comments/49xpy4/lingq/), one of the bigger problems listed being that the translations are mostly user-curated and there is both a lack of interesting Korean content to import and the language has many conjugations that make words different from each-other, reducing the amount of translations in the system. That Reddit user pointed to http://lwt.sourceforge.net/ as a possible free alternative, mentioning that the user content is the only advantage of LingQ over this application. This, however is an application for computers and not smartphones. The technique promoted by LingQ is a sound one though, so you may want to play with it a bit and decide for yourself if it works for Korean or not.
I would also suggest trying some alternatives that might give a somewhat similar result, while being different in their exact use.
I have looked for a replacement to the apps I've found useful for other languages and came upon Lingodeer. It is not a word-for-word reader, but there are "Story" exercises that allow you to either read a text sentence by sentence with images to give context, or to speak out what you should have just read. The follow-along is not quite what you're looking for, but not too far and it is quite hard to find good content for east-asian languages in other apps.
I have not tried it myself because of a lack of videos to convert, but subs2srs (http://subs2srs.sourceforge.net/) seems like a good way to generate content for yourself. It turns the translations accompanying a TV show or movie into flashcards for Anki or other apps. It will not result in a word-by-word translation, but will give you a sentence-per-sentenceish translation and will be able to generate sound and video clips to match them. This would allow you to turn TV shows you have video files for into Anki cards, a version of which exists for Android and iOS. https://www.gomlab.com/subtitle seems to be a good source for translation files.
I think Learning Korean from an website or application is some what difficult. You can use LSRW rule.
LISTENING - You should Listen to Korean News channels and KDramas to understand how to convey your message in Korean.
SPEAKING - You can find some native Koreans and make them as your friend to develop your slang.
READING - Acquire Basic alphabets from Elementary stage , then start reading Korean Newspapers. This is one of the Crucial step to excel your skills in korean Script reading
WRITING - Use Online Korean Keyboard with spell checker to write korean Efficiently.