I don’t really like Apple, but once in a while they do the right thing. This comes from the App store’s new labels on apps.
Signal just has “Contact info” under the “Data NOT linked to you” category. This is just the phone number + contact discovery.
UPDATE
There’s another post adding telegram here. This is what it looks like:
That’s interesting. Doesn’t Signal require a phone number to create an account?
Yes, but that’s just it. They don’t link it to your name (The name you enter is only shared with the people you message, and is encrypted).
They also use your contacts contact discovery, so you can seamlessly start sending Signal messages to you address book. Once again they use the as little info as possible (the phone numbers are hashed). You can have more info about why private contact discovery is hard here and a potential solution here.
This is mentioned in the app store, but under the category “data NOT linked to you”