It was a bundle in a select few European countries. I got my pixel watch for free with my pixel 7 Pro imported from France.

I used misskey for like a year before switching to calckey and can't recommend it enough. Misskey has a lot of questionable choices (like you still can't click on notes to open them like every other software, or the sub-par mobile interface) and it's also the only *key that doesn't support note editing despite everything else supporting it. All in all calckey provides a much better experience.

For mastodon no. Husky was specifically made to be compatible with certain pleroma features (emoji reactions, unlimied attachments, stickers, etc.).