Yes! Read a book out loud, preferably to your kids, recording each chapter as a file. Then use m4b-tool to combine all the chapter files into a full audiobook.

They have updated it so that you don’t need to use your phone number as the identifier you share with other people so that they can message you. You can now give out a username and your new contact will not be able to learn your phone number.

As for Signal itself knowing what your phone number is, I don’t see that as much of a problem, because they intentionally don’t know anything useful about you. They publish redacted subpoenas and their responses so you can see just how little data they can provide. They don’t know who your contacts are so there’s no social graph to be drawn.