Is a changelog available?
All I can see on Amazon is:
"The software update includes general improvements and the following feature enhancements:
Enhance your device's security with encryption
You can now encrypt your accounts, settings, and downloaded apps and their data, media, and other files on your Kindle Fire. To learn more, go to Protect Your Data with Security Settings.
Test your knowledge with Flashcards for Kindle Print Replica textbooks
Create flashcards to help you learn more about key terms and concepts in a textbook. To learn more, go to Reading Enhancements."