Make Signal even more private
If you're using Signal, there are privacy settings worth looking at. (and if you're not using Signal, listen to Super Simple Security Principles episode 20, Signal: A Safe and Private Communication App).
Under Settings –> Privacy –> Phone Number, you can choose who can see that you're using Signal. The Signal default is that only people who have your phone # can see you. You can change it so that by default, nobody can see you're on Signal except people you've contacted directly.