Deep English is a website for learners of English created by American teachers Dan Douglass and Aaron Campbell. Their mission is "to get you passionate about using English to communicate and understand real, meaningful ideas." Watch this video to find out more about the Deep English method.
The co-founders make a point of saying that their lessons are "for people who are open-minded and ready to make the jump to English fluency", adding that "this isn’t for beginners." The Fluency Course costs $99, but there are a number of free lessons available, each delivered at three different speeds, with transcripts and downloadable audio. There are also some extra resources for teachers and for students. I signed up for the free 7-day email course just to try it out and was impressed not only by the quality of the lessons but also by the advice on how to improve your listening, speaking, and pronuncation skills.
If you're a learner at upper-intermediate level or above (B2-C1) and want to take your English to the next level, I would definitely recommend having a look at Deep English. At the very least, you should check out the free lessons (also available on YouTube) and sign up for the free email course, which may well introduce you to you some learning techniques you hadn't thought of.