Zippy, I’m hugely in your debt for many postings over many years, so I am hesitant to offer a different view on something. Amazon’s new UI option allows you to long-press the Home button and then click OK, and be taken straight to a simple alternate UI grid of all your apps (which can be arranged in any order you like, much like Roku). The best thing is NO ads in this interface.
So you’re pressing two keys, 1-2, instead of 1 for Roku, but it takes about the same amount of time, and the resulting UI is even simpler than Roku’s. (And, yes, I wish you could turn off the default screen to avoid even thinking about it, but through this alternate UI we never look at it except to play an Amazon video.) I moved over from being a years-long Roku fan (6 devices) when I stumbled upon the new Fire UI option and in my view a (currently) better default Tablo app.