Lying about being the first phone app with E2EE (they're not even close, by over a decade if we count J2ME apps) because Signal was called TextSecure back when telegram didn't even exist yet. Lying about their protocol, lying about their backup system (if you're using group chats or regular chats which are backed up they are visible to the admins and any other claim is a lie), bullshit propaganda against Signal, etc...
Oh and by the way, Signal has now finally launched usernames, so you don't have to share your phone number to use it anymore.