You can launch Kodi from the home screen on the fire tv
Create new event
add new condition and choose Active application Then choose any app you want to trigger Kodi to open. I used Curzon Home Cinema
add Action and choose Run Application The choose Kodi
Now test you will see that when on the home screen you click Curzon and Kodi will open instead.
This is really handy and saves you time going in to application and launching it from there.