@krutonium The only one I actively use is https://stefanbohacek.com/project/mastodon-tools-browser-extension/, which I made myself. It lets me switch back to my home server whenever I find myself viewing a post or a profile on a remote server.

It had other features, that have been since implemented in Mastodon, like hovercards, so hence the more generic name.

I know there is also https://streetpass.social, which is pretty neat for finding more people to follow, and https://chromewebstore.google.com/detail/graze/epocinhmkcnjfjobnglchpbncndobblj, which has a bunch of features, I just don't really use either of these myself.