We've been recently working on an app that makes it super easy to catch and learn unknown English words and expressions from virtually any movie or TV show. The point is exactly to sound sophisticated as a native person rather than sounding like someone learning from text-book like English. And since we build it on top of the habit of watching movies, we believe it will simply integrate into one's daily routine. Any feedback is welcome since we are not 100% percent sure, where to go with this :) It is available for free on iOS and Android:
https://play.google.com/store/apps/details?id=com.skeebdo.learn.english