Doesn't seem to work.
The Developer Certificates Bundle are only for Kindle Paperwhite: Firmware 5.2.0 - 5.3.4
I do get the Cool Reader book on my Kindle OS Shelf, but when I click it the screen goes black for a few seconds and then normal again.
I've followed these directions:
Cool Reader 3 for Kindle Paperwhite and Touch.
1. Follow the instructions from Collections Manager. Ensure it works on your device.
2. Download cr3-kindle-2012-10-04.zip, unpack, copy cr3, qtKindle, usrapp directories to the Kindle drive root. It's a base older version.
3. Download/clone GitHub repository.
4. From dist-kt folder copy all the files to Kindle (overwriting existing files from step 2). It's the most recent version update.
5. Run Cool Reader from the shelf.