Default Optimum App

I was hoping to load the Optimum app on my Fire TV, to see if I could watch TV from it. I tried installing the version from Google Play, but it launched in portrait mode, then said "this display is not supported" and exited.

I was thinking the Kindle Tablet Edition of the app might work, but I can't find the apk.

Has anyone gotten this to install successfully? If not, would anyone be able to help me fine the Kindle Tablet Edition of the app and I'll try myself?

Thanks!