Just performed a jailbreak on my Kindle Basic 8th Gen (KT3) running firmware 5.13.6. I had to perform a serial jailbreak took 7 hours but was definitely worth it. KOReader is 100
Jailbreak released for Kindle running firmware version 5.14.2 or earlier - Liliputing
List of Best Custom ROM for Amazon Kindle Fire HDX 7 [Updated]
New Jailbreak Released for All Kindles, Including Kindle Scribe