Hey - just wanted to pass on a way to send a pop up message to the Fire TV from Tasker using an app I released called Signal for Fire TV. This example shows how you could send a message to all the Fire TVs in your house when you get home using Tasker's Send Intent action. It will show the popup regardless of what is running on the Fire TV.
I've developed apps for both the Roku and Chromecast, and I think the Fire TV has greater opportunities for automation since it's running a full version of Android, and because it supports multitasking. I'd also appreciate any suggestions for additional automation options for the app. Things I could do pretty easily would be to launch a particular app, or show a video or photo.
-Gregg Reno