[systemicdanna]

This looks very promising. In addition to using KOReader I will be able to customize the lock screen and remove Amazon's upsells. I guess the only downside is that I won't be able to use WiFi or buy e-books from Amazon.

[Vrondi]

Also, Koreader runs on many brands of ereaders, so it may be worth exploring if you're interested. Kobo readers can read non-DRM epubs out of the box and can also run Koreader. Check out the MobileRead forums. Here's the one for Kindles: https://www.mobileread.com/forums/forumdisplay.php?f=140