My novella length serial story, The Starfaring Life, is now available on Amazon's Vella platform. It can be read on the Amazon site here: https://www.amazon.com/kindle-vella/product/B0989VDP6N
It can also be read on an iOS Vella app which will allow it to be read on your iPhone or iPad. The first three episodes can be read for free, after which you will have to spend tokens, one per hundred words, to read the rest. I believe that at least on the app, Amazon is offering 200 free tokens at launch, which if true would allow you to read almost the whole story for free.