It's not - I'm running this on an Amazon device:
Fire Tablet with Alexa, 7" Display, 16 GB (Previous Generation - 5th) L-2338
( https://www.amazon.com/Fire-Tablet-Alexa-Display-Black/dp/B018Y22BI4 )
Will it not be possible to post a review unless I install it on my phone? IE, continue to use my Alexa tablet as my podcast station (which I love it for and that's its only job), but maybe just log in on my phone only to post reviews? Will this be the only way to post the occasional review, you think?
I'm not willing to jailbreak the Alexa tablet, since this is it's one job and it's perfectly wonderful for this very specific use case. So if a dummy install on the phone for review is the only way to review, that's not ideal, but it's not a deal breaker.
You could use Drives. Here's a screenshot from my podcasts directory