Hacks [K4NT] Kindle 4 Kindlet Launcher — Standalone .azw2 app shortcuts for K4NT

[Den_Switch]

hi everyone,

I'd like to share a small utility I vibecoded (sorry!) for owners of the Amazon Kindle 4 (Non-Touch / Black / Silver, FW 4.1.x):

Kindle 4 Kindlet Launcher
GitHub: https://github.com/DenSwitch/kindle4-kindlet-launcher

author's note: I wanted to be fully transparent: this project was created entirely with AI assistance. i had the idea and needed a simple launcher on my Kindle 4, but don't know how to code java bytecode patching and signing myself. I'm sharing it here in hopes that it helps fellow K4NT owners!

what this tool does
a python script that generates a signed .azw2 Kindlet book. when you open this book from your Kindle Library, it executes your shell command or script (like starting KOReader or toggling USBNetwork).

pre-built launchers:
if you just want working launchers without running python, there are two ready-to-use files in the repo:

• KOReader.azw2 — starts KOReader.
• Toggle_USBNet.azw2 — toggles USBNetwork / USBMS.

just copy them to your Kindle's /documents/ folder.

requirements:
jailbreak + MobileRead Kindlet Kit (MKK).

building your own launcher:
requires python 3 (pip install cryptography pyasn1 pyasn1-modules paramiko):

python make_launcher.py --name "KOReader" --cmd "/mnt/us/koreader/koreader.sh"

(optional: add --upload <Kindle-IP> --ssh-pass <PASSWORD> to transfer over wi-fi).

feedback, suggestions, or reports on other KDK 1.0 devices are very welcome! :)

[Frogm4n]

I tried the KOReader.azw2 launcher on my K4NT and it opens it just like I'd expect. I did have to follow the prompt to press Back twice after exiting, though the text of that was overwritten on other stuff and difficult to notice at first.

[Den_Switch]

Originally Posted by Frogm4n

I tried the KOReader.azw2 launcher on my K4NT and it opens it just like I'd expect. I did have to follow the prompt to press Back twice after exiting, though the text of that was overwritten on other stuff and difficult to notice at first.

great!
regarding the text, initially i wasn't planning to add it; once you know how to exit (by spam-clicking back button or just pressing home), you won't even notice those instructions haha. shows for me without any problems though