I play Blades on my iPad 5, and I also had it installed on my older iPad 2 until Apple decided to do whatever they did that triggered my iPad 2 to insist on being "activated" all over again, which I haven't done yet.
I haven't tried installing Blades on my B&N Nook HD+ tablet with dual boot card that lets me run Android 4.whatever on it, mainly because I must have changed my Google Play password so I can't install or update anything anymore, and I haven't taken the time to reset my password because I hardly ever use my B&N Nook HD+ anyway.
I just bought an Amazon Fire 7 during Prime Day, but I hadn't even looked to see if TES:Blades is in the Amazon Appstore. I've checked just now, and I'm seeing neither Blades nor Legends in the Amazon Appstore.
![Sad :(](./images/smilies/icon_sad.gif)
As far as running Blades on phone versus tablet, I'd say that it's definitely better suited to the larger screen of a tablet.
ADDENDUM-- Both Blades and Legends are listed in the Google Play store, and I know there are videos that talk about how to install apps and games on Fire tablets using Google Play rather than the Amazon Appstore, but I haven't tried that with my new Fire 7 yet-- and there's no guarantee a given Android app will be compatible.