It freely provides the carrier information. Just tried on my real phone and app. Worked for an American number in my call history too, but gave no info for a Mexican one. 3/3 it gave the correct provider info. This is what shows for my app whereas my cell comes up as “mobile”and “Rogers.”
I just invented a burner app called Poontango. If you get a message with “sent by Poontango”, I recommend you delete the message. Nothing good can come from Poontango; unless you choose to live dangerously.