Not sure how I feel about this being a standalone app, it already feels like there's so many vying for attention, with IRC, XMPP and Matrix being federated already. While Signal exists, I'm not sure how I feel about it being a walled garden despite being open source.

I do love the idea of it hopefully being added to Fediverse platforms though - even though it makes sense to use an actual messaging app for messaging, it's user expectation that you can just message people on any platform you're on easily, it's something Mastodon desperately needs.

Edit: Really though, what I want to see is an interoperable protocol being picked (Signal is actually one of them, FWIW, the Foundation just doesn't federate with its flagship app due to "user experience and innovation" per Moxie), and then people make their platforms on that, just like how ActivityPub has become the standard for interoperable social media.