https://signal.org/#page-top
Passos para instalação
# curl -s https://updates.signal.org/desktop/apt/keys.asc | sudo apt-key add -
# echo "deb [arch=amd64] https://updates.signal.org/desktop/apt xenial main" | # sudo tee -a /etc/apt/sources.list.d/signal-xenial.list
# sudo apt update && sudo apt install signal-desktop
