With Fire OS 5 for the Fire TV and Fire TV Stick announced only a little while ago, here’s a list of things we already know about the update and developer preview.
Based on Android 5.1 Lollipop
Fire OS 5 is based on the latest version of Android, which is version 5.1 Lollipop. This means developers will have access to the latest Android APIs, which are level 22. The current Fire TV OS is based on Android 4.2.2 Jelly Bean which uses API level 17. This means the latest Android apps will run on Fire TV devices without much customization, ensuring the Fire TV app selection stays updated.
Supports Android TV and Leanback Library
Fire OS 5 for Fire TV will support apps created for Android TV. This includes the v17 Leanback library, which allows developers to easily create TV friendly interfaces. This means Android TV apps will be easy to port to Fire TV devices.
Developer Preview can be rolled back
If you install Fire OS 5 Developer Preview, you can easily roll back your Fire TV device to the current latest software version based on Fire OS 3. All you need to do is fill out this rollback form with your Fire TV serial number, and your Fire TV will receive an over-the-air update that re-installs Fire OS 3.
Rolling back to Fire OS 3 will force a Factory Reset
If you install the Fire OS 5 Developer Preview and then later decide to roll back to Fire OS 3, you will be forced to factory reset your Fire TV. This means you will lose all of your apps, app data, and settings.
Latest Fire OS 3 required to install Fire OS 5 Developer Preview
This forum post by an Amazon representative seems to imply that, in order to install the Fire OS 5 Developer Preview, your Fire TV device needs to be running the latest version of Fire OS 3. Currently, the latest version is 220.127.116.11 for the Fire TV and 18.104.22.168 for the Fire TV Stick.
Fire OS 5 Developer Preview contains no new features
The purpose of Fire OS 5 is to keep the Fire TV compatible with the latest great apps made by developers. It is not being released to add any specific features. You will likely not notice any changes between Fire OS 3, which is currently on Fire TV devices, and Fire OS 5.
Fire OS 5 will install via a standard OTA update
Fire OS 5, the Developer Preview, and updates to both will be installed via the standard over-the-air update process used by Fire OS 3.
Fire OS 5 will not support all Fire OS 3 apps forever
Certain aspects of the Fire TV software development kit are being deprecated with Fire OS 5. At first, Fire OS 5 will fully support all current Fire OS 3 apps on the Fire TV. But at some point in the future, the older Fire TV SDK add-on will no longer be supported. This means apps will be forced to use the newer APIs if they want to work with the latest Fire TV software version.