There are two amazing tools that help you find your Twitter followers (and list members) over at Mastodon:
1. https://debirdify.com by
@pruvisto
2. https://fedifinder.social by
@Luca

I've just registered the above two simple URLs to make finding/remembering these sites easier.

The original URLs are: pruvisto.org/debirdify/ and https://fedifinder.glitch.me it doesn't matter which URL you use, they'll end up in the same place.

fedifinder.social hasn't quite propagated yet