Why I decided to write about this topic

Maybe you are a hard working person and your schedule is very tight, so you have little time to train yourself.
Maybe you're a student who is constantly busy learning, and you're still keeping yourself afloat with side jobs.
And the answer to this question is, how do I structure learning in a way that is as easy as possible and achieves the greatest possible learning success?
In order to get an answer to this question, I have put together a system that allows me to acquire large amounts of knowledge as efficiently as possible.

What material do I need to achieve this?

1. A good ebook reader app

Why is this so important? To understand this I would have to explain the system as a whole to you first, so much in advance: The ebook reader app is the decisive one, because it is of crucial importance for the system I suggest to you.
What choice did I make?
Moon+ Reader Pro
Why this app?
To highlight the advantages of this app you only have to look at the documentation.
No other app is able to handle the tasks that are combined here.
For us, however, only the following are important for the time being:

1. If possible, it must accept all file formats that we require
2. It must allow seamless integration with dictionaries, Wikipedia, search engines and word processing (e. g. by sharing).
3. it must offer me ebook sources, and support a Calibre with as short a detour as possible.
   

2. A good dictionary supported by the ebook reader

Since our choice of the ebook reader app has already been made, we need a suitable dictionary app.
My choice:
GoldenDict
Why did I choose this app?
You can download a large number of popular dictionaries, integrate them, and determine the order in which the results are displayed. You can also download a trial version of well-known dictionaries on the following page, for example:
https://web.archive.org/web/20110125090641/http://www.babylon.com/dictionary
After you have downloaded the desired .exe file, you can open it with a file archiver such as WinRAR or 7-Zip and use the .bgl file it contains on your phone with GoldenDict.
Also here you can download a huge selection of free dictionary files:
http://www.babylon-software.com/free-dictionaries/

3. A functioning Calibre

In order to organize your books on your PC and convert them if necessary, a Calibre is recommended. Since I have to summarize myself, here is just a link to the corresponding tutorials:
Combine Dropbox & Calibre For Universal Access To All Your E-Books
How to use Calibre - a look at its features and user interface

4. An app that gives me access to my Calibre from my mobile phone

Calibre Companion

How do I set it up?
Just connect to the dropbox account that contains your Calibre library, and you can simply download the books from your local Calibre to your mobile phone.
Make sure that the folder for importing books into Moon+ Reader is the same as the folder for downloading Calibre Companion.

5. An app to create and learn over flashcards

My choice:
AnkiDroid Flashcards
In order to learn efficiently, this system has a good algorithm which allows you to determine different levels of learning in order to achieve a dynamic learning success.

Scenario on how to use this system

Buy a book, or download it, load it into the Calibre, and customize the tags, then convert it to the appropriate format, download it to your device via Calibre Companion, import it into the Moon+ Reader, read and translate it using the dictionary, copy the content into an AnkiDroid flashcard via the "Share" function, and repeat what you have just learned with the existing algorithms to consolidate what you have learned.

Have fun learning! Ask if you have any questions in the comment section.