My wife bought a kobo as it allows her to use the local libraries ebook collection, rather than spending hundreds of pounds at amazon for the kindle.

It was starting to die and had screenglitches. After a bit of debug, it turns out that hacking the kobo is dirt simple. You open up the back, and replace the SD card. thats it.

There is a large community that have created toolchains and guides. there is of course a port of koreader (https://koreader.rocks/) which has a lua interface for making your own apps.