ReadLang (app) is AWESOME. Read an article of your choice or one from their library (some even have videos for audio) and click on the words you don’t know. Translations are automatically generated so you have to allow for them being incorrect sometimes. It can show dictionary entries as you read and will add words you clicked on to your flashcard deck. Korean is still in Beta but looks good. ReadLang Web Reader also lets you translate words on any webpage. 

Whilst I’m here I’ll mention a couple of chrome extensions I use:

1. Toktogi (똑똑이) Korean-English pop-up dictionary. Hover over Korean words on any page to see definitions. Automatically generated translations are sometimes incorrect.

2. Flewent. A certain percentage of words on any page are translated into your target language. You can then hover over them for the definitions. (also Lingua.ly seems better but this doesn’t have Korean yet). Automatically generated translations are sometimes incorrect. You have to be especially careful with this because it translates words out of context. 

3. FlashTabs. Create a set of flashcards and view one every time you open a new tab.