the kindle platform doesn't run the app as is. You have to have an android or IOS. So you have to change the software on it to add (windows?) something?
I tried to get my Amazon Kindle to run it like some others have, and never did. I went to strictly android.
I have a Samsung Galaxy tab E 8" and the larger Samsung 11" tablet running the app along with some phones. I grab the phones for convenience. I have the larger tablet on a stand also for convenience (one hand). The tab E stays with me upstairs. I got most when family upgraded to new ones.
I think what ever size you run, you'll adapt to. The phone is the easiest to "grab and run" with.