it's not the easiest tool in the world to make, but i *think* it's doable.
Discussion
why would it be difficult if your followers all publish their relay list?
or is it difficult to identify followers?
trying to learn ...
(oops, accidentally reposted that instead of replying)
one relay wouldn't necessarily know about all your followers. and you might even have followers on relays that you're not directly connected to.
figuring out exactly how far your posts is reaching is what my https://nrcheck.tigerville.no tool does. i don't publish to all the relays that are listed there for my posts, but i might still have followers who use them.
