Signalator

Private Messenger может быть скрыт.

Signalator is a free Messenger that can be hidden, send and receive high-fidelity messages, participate in high-definition voice / video sessions, and stay in touch anytime, anywhere.

Disguise Signalator icon function (make Signalator not easy to be found, disguised as calculator icon and have calculator function)

You can use existing phone numbers and address books to communicate securely with your friends.

  Fast and efficient-Signalator can send and receive messages quickly and reliably.

Advanced end-to-end encryption (powered by open source Signal Protocol ™) ensures session security.

Open source address https://github.com/torny10/Signalator-Messenger/