thecatinabox

You can create app's on them, either native apps built for armv7 (and an old version of glibc), or create a 'kindlet' (java app made for kindles, using java 1.4 (or 1.5 if you compile it down to 1.4))

https://wiki.mobileread.com/wiki/Kindlet_Developer_HowTo https://cowlark.com/kindle/getting-started.html

At my current job, I made an app for the older Kindle 4, as a way to replace paper pick lists. It ends up being both cheaper then paper + ink and more convenient. It's also a nice way to recycle old/unused kindles.