Learning languages (reading/listening) by reading epubs

Hey all, I was looking for an useful app that helps me improve both my language learning skills in any language, by reading epub files. It's called Smart Book. available for smart phones Here is the directing link:

https://smart-book.net/app/6e24d

The steps are simple:

Upload your e-book file. Then you can open the book immediately.

When you tap on a word, a window pops up. There you can see the meaning of the word and whether it is used as an adjective, adverb, or verb.

It even explains the word's context in the sentence with AI (this feature is premium).

There's also a translate and voice button next to each paragraph. When you tap it, it translates or reads the paragraph aloud. (I liked the voice feature; they've used Google's voice engines, which is quite important for learning correct pronunciation).

You can also change the paragraph translation buttons in the settings to translate sentence by sentence. This is better for beginners.

You can upload any e-book file you want or read from the ones already saved.

PDFs are not supported, but you can convert them to an e-reader format using a program and then use them. (This will save you if you can't find the epub file for the book you want.)

I've been using the app for a long time. There are many more customization settings in the menu. The menu language is a bit confusing, except of English. If you have any other questions, I can answer them.