Probably because they are apple snobs or something.
My wife’s ipad 3 can get the app from the itunes store but it currently won’t play videos it will however allow us to watch them via Safari. On my Gs4 and Kindle Fire HDX 8.9 there is no app available on Google play or Amazon and you cannot watch any shows from any browser. I have also tested this on a nexus tab and Galaxy S tab with the same result. It’s almost as if they are purposely blocking android devices. I say that because when I tried the Maxthon browser it has the ability to mask itself as another device and when selecting ipad as the device ID the video’s audio track will play but no actual video plays. Then there is the ongoing thread of three years requesting for Roku app to be released. and still no dedicated TAN channel. Roku Channel
Granted I could watch TAN content on the Hulu channel but I refuse to pay them for the privilege of watching commercials.