It's not that hard to free your kindle. :)
See: https://kindlemodding.org/
I recommend you try it if your kindle is supported by the jailbreaks.

I use #KOReader (https://koreader.rocks/) on my Kindle, and I like it far more than Kindle's native interface.
KOReader is also available on other platforms (e.g., Android, Linux) so you can try it there first!
It can even synchronise reading progress between devices, so I can resume reading on my tablet/phone. :)
(yes, I shill koreader. its awesome)

CC: @viq@hackerspace.pl