ADB Performance Tweaks
We can use ADB to improve the performance of your Amazon device. On FireOS 5.x device, you can not make a ADB connection directly on the device itself, you have to do it from another Android device / emulator.
On your alternative device install Remote ADB from here
Find the IP address of your device by going to Settings — My Fire TV — About — Network
Ensure you have enabled ADB enabled in Settings — My Fire TV — Developer Options.
Open Remote ADB and enter the IP of your device on port 5555

Once connected enter in the this command:settings put system transition_animation_scale 0.0
click Run
Ensure there are no errors and then enter in the 2nd commandsettings put system window_animation_scale 0.0
Finally enter in the final commandsettings put system animator_duration_scale 0.5
click Run
The 3 commands will turn off the Window and Transition animations which will give you quicker UI performance
You will need to reboot your device to apply the change
Cool Start Page
Use the following link in any browser:
FireOS 5.x Debloat Tool
This debloat tool will uninstall the following 15 processes on your FireOS 5.x device
com.amazon.bueller.music
com.amazon.bueller.photos = Amazon Screensaver
com.amazon.kso.blackbird
com.amazon.ods.kindleconnect
com.amazon.tv.csapp = Help related
com.amazon.tv.support
com.amazon.vizzini = Amazon Voice Support (Alexa Media Player)
com.amazon.ftv.glorialist = Gloria
com.amazon.tv.livetv
com.amazon.aria = Aria AriaRuntime
com.amazon.hedwig = news
com.amazon.alexa.externalmediaplayer.fireos = Alexa Media Controller
com.amazon.tv.alexaalerts = Fire TV Alexa Alerts
com.amazon.tv.releasenotes = ReleaseNotes
com.amazon.tahoe = freetime
Download the tool from Here
On another Android device (i.e not the device you want to debloat), open the debloat toolbox

Again, enter in the IP address of the FireOS 5.x device and click on connect

You will then see the above on your device. If you don’t see that prompt, turn off ADB debugging, wait for 10seconds and then turn it back on. Click on connect again on the Toolbox.

Please take a note of the warning – if you notice something stops working after running the debloat tool – you will have to reset your device back to factory defaults
Ensure you see the Connected message & click on the box on the top right to select all 15 processes:

The debloat tool will now uninstall all of the selected items:

Reboot Your Device Shortcut
Press the select and play button together for 5 seconds and that will fully restart your device

Watch the apps in action here: