The update to version 6.3.1 should automatically be installed on the device and if it isn't, you can go to the sourcelink for instructions on how to manually download it. After the update, you will find Parental Controls which allows you to password protect certain functions like streaming video and even making purchases at Amazon's Appstore. With password protection enabled, the user will have to enter a previously set password to make a purchase, or stream video. Parents can also completely block functions like Web, Newsstand, Books, Music, Video, Docs and Apps. On the main Kindle Fire screen, any function blocked will be "grayed out" and will be unavailable for use.
There are other new features being added to the tablet with the update, including the ability to share specific parts of a book that you are reading on the tablet, to your social networks. Students will now be able to buy print-replica text books at a savings of as much as 60% over the cost of buying the textbook and the clock for renting a video now starts ticking once you begin to view it instead of when you downloaded the video as in the past. You can view the entire changelist at the sourcelink.
source: Amazon via MobileBurn