After some random searching on the Android TV App Store, I happened to stumble across the History Channel, A&E, and FYI app. I was able to successfully install it on my Shield Android TV. The app requires a cable login but it definitely works!
Google Play Store - History Channel install link
Google Play Store - A&E TV Network install link
Google Play Store - FYI install link
Do they require cable logins?
Pointless, if so..?