Hi herrm,
It´s daily “high-volume” reading-while-listening (ca. 8-10k words read and listened to a day - at least with languages that have a familiar writing system) that is based on
- habits
- timeboxing (2 Pomodoro blocks à 25 min a day)
- content flexible audio reader software (LingQ, ReadLang, etc.)
- a combo like “audio book + e-book imported into the audio reader” (or “podcast + transcript”, etc.)
- where the audio speed (> 1.0x - 1.5x) is a kind of “pacemaker” for the reading speed.
However, this approach isn´t suitable for the beginning stages (A1-A2), but it´s designed for the intermediate level B1 to achieve an advanced level (B2-C1 / C1) in listening and reading comprehension in the most (time-)efficient way.
In short: It´s a kind of accelerated mass immersion technique.
I´m working on an e-book version right now. However, here are some of the basic ideas (from my reply to @tjbandel from the “feeling-demotivated”-thread: https://www.lingq.com/de/community/forum/open-forum/feeling-demotivated):
"it mostly feels like a chore which needs to be done, and I am learning for a purpose as per say, not because I particularly find it 'fun to learn languages'." (tjbandel)
You should be aware that there´s a lot of marketese in all types of skill acquisition products (languages, math, fitness, etc.).
Everything is the "fastest, easiest, and most fun way ever".
Learners who fall for these promises tend to have two types of experiences:
-
If it’s fast, easy, and fun, it’s more or less useless because learning a challenging skill is, well, “challenging” 
-
After a few hours they see:
- it´s not fast, but time-intensive
- it´s not easy, but they´re confronted with increasing levels of difficulty
and
- it´s not always fun, esp. at the beginning of the learning process.
So if learners aren´t able to adapt their mindsets to the learning realities the´re confronted with, they´re toast.
In my teaching experience, many learners aren´t able to change their attitudes. Why? Because “the feeling like it” mindset is itself an established bad habit 
So what can you do? Here a few tips:
-
Switch to a habit-based approach. Let´s say 2 Pomodoro blocks à 25 min 5-6 days a week.
I repeat: If you don’t tackle this attitude problem, it doesn’t matter if you take a few weeks or months off, because you’ll be faced with the same demotivation problems over and over again - in short, they’ll haunt you!
-
Use quantifiable metrics as goals, not some “vague feeling of fluency” (that´s like trying to nail a pudding to the wall).
As a native speaker of English with Polish as your L2 that would be something like:
- ca. 3 million words read
- ca. 500 hours listening
- ca. 100 hours speaking
- Use an ultrareading-while-listening approach (= “book / audiobook” - combo) because
- it´s very (time-)efficient (you read and listen simultaneously and you read a lot)
- it improves your “focused attention” more than reading / listening alone
- it works as a “natural SRS” because of the high volume of words read
-
Use a time-boxing approach, esp. Pomodoro is your friend here.
If you practice “ultrareading-while-listening” in 2 Pomodoro blocks (25 min each) per day, 6 days per week, you will have read between 2.4 and 3.1 million words after one year (tip: you should strive to read about 4-5k words per Pomodoro block by increasing the speed of the audio to 1.2, 1.25, etc. on Audible, Youtube, LingQ, etc.).
-
Choose at first interesting / fascinating non-fiction texts (e.g., the Harari trilogy mentioned above), then contemporary (popular) fiction that you find fascinating. If it´s the “Witcher Saga” in Polish, then go for it 
-
Tweak this approach a little bit by:
- exporting the LingQ flashcards to Anki. Usually 5-10 min of Anki a day can be quite helpful. Or if you need some grammar / verb conjugation drills, check the free decks for Polish on Memrise.
- listening to other Polish content (the news, podcasts, whatever) 30 min a day in your down time (while ironing the clothes, washing the dishes, etc.)
- speaking (at first self-talks where you try to summarize what has been read, later Italki and Co sessions) for another 30 mins.
I don´t mention writing here, but chatting, for example, is also your friend.
If you can do this for about a year (and I repeat: a habit-based learning style is a “best practice” in this context!), ca. 2 hours a day, ca. 6 days a week, all your stats on LingQ will skyrocket.
Then you should be at B2-C1 / C1 level in Polish. In comparison, you’ve only reached about 20% of this language learning journey at the moment!
If that´s too much every day, just go for 1 Pomodoro block à 25 min a day. But then your language learning journey will take a bit longer.
Hope that helps
Peter