@tomminieminen @rejzor Oh dear, I just saw that it's not even Signal. As Heather Cox Richardson said:
"Yesterday I identified incorrectly the messaging app newly fired national security advisor Michael Waltz was using at a Cabinet meeting on Wednesday as the unsecure Signal app. Joseph Cox of 404 Media identified the app as “an obscure and unofficial version of Signal” from “a company called TeleMessage which makes clones of popular messaging apps but adds an archiving capability to each of them.” As Josh Marshall of Talking Points Memo notes, this third-party app introduces even more insecurity into those White House communications."