Ok so I am not big fan of Amazon. I have bought a few ebooks on Kindle for small romance writers since that's where they're selling their ebooks. But outside of the stuff I get cause it's only on Amazon, I tend to prefer to avoid kindle.
So as yall know, I recommend various alternatives for reading ebooks in the language you're studying:
Pleco - if you're studying Chinese this is one of the best options. It allows you to read web pages, and ebooks pdfs etc, has generated audio for words and the entire text, great definitions, and can Google translate passages.
Kyreader - free ebook reader for ios. Features a good click dictionary/translation of words, generated audio for the entire text. Can generate audio and recognize text on pdf files which is nice. I've tested it for chinese, French, japanese and it worked well for all 3.
Moonreader+ - one time purchase ebook reader for Android. Features a good click dictionary (once you figure out how to set it up), generated audio for entire text. Seems to work as well as Kyreader. (Only thing is I do notice I need to go in and manually change my phones text to speech language whenever I change the language I'm reading and want generated audio).
Idiom - free web page reader and YouTube video dual subtitle tool. Features click dictionary (its as good as lingq but not as good as Pleco), generated audio for text, and for youtube videos features translations for each line and ability to replay any line/skip to various lines. It is less perfectly tailored for chinese than pleco, but overall for Any Language Immersion I recommend this app. It works about as good as lingq, but Idiom is free. (Only thing I do notice is on android I have to change my text to speech language on my phone settings depending on the language I'm reading in Idiom if I want generated audio, on iphone the generated audio automatically spoke in whatever language I was reading).
Now. There are a couple particular reasons I do like lingq and Kindle in... some ways for language learning.
Lingqs coolest feature, in my opinion, is how it COUNTS the amount of words you've learned/looked up. So you can track your progress. However, lingq has a lot of weak spots in my opinion. I prefer to recommend dongchinese for chinese learners if you want the word learned tracking feature, or perhaps Readlang for language learners generally (though I have not explored Readlangs features much).
What I like about Kindle? 1. I can buy Japanese ebooks on amazon.jp and read them on kindle... which is the easiest way I've found japanese ebooks (print books are easier to find but then I can't use digital click dictionary tools). 2. Once you figure out HOW to set up amazon.jp and a corresponding Kindle account, Kindle has very good definitions (they are lacking pinyin for chinese though). There is no audio in the click dictionary in Kindle, which sucks compared to Pleco (or idiom), but the overall extent of definition quality is quite good (better than lingq and idiom). Kindle also has a feature that tells you how long it is taking you to read each section, and based on your reading speed then how long until you finish the novel! This particular feature is so cool to me! Because often a difficult part of reading in a target language is trying to figure out how much time I need to plan to set aside to read a chapter or X pages, and how many hours a novel is going to take so how many hours I need to read per day to finish that novel in a reasonable time frame. Just an FYI if you were looking for that specific feature, Kindle has it.