There's also Royal Road, Medium and Patreon (though the latter can't really be used on its own).Finally, there are many apps like this, mostly based out of China. I say that because you would be subject to Chinese laws. Radish is in the US.
And then there's substack, which should be a category all its own. I just started experimenting with that (see banner in my sig) and will keep you all posted on how it goes.