Apps: Signal

Last updated: September 29, 2025

Summary End‑to‑end encrypted messenger for texts, voice, and video. Uses the Signal Protocol with advanced properties like forward secrecy and sealed sender.

Maintainer

Signal Messenger LLC

Repository

Client (Android): https://github.com/signalapp/Signal-Android
Server: https://github.com/signalapp/Signal-Server

History

Originated as TextSecure + RedPhone by Open Whisper Systems; unified into Signal and later stewarded by the non‑profit Signal Foundation (2018).

Why use it

Strong defaults for private messaging and calls; wide network effect among privacy‑minded users; disappearing messages; registration lock PIN.

Safe use

Enable registration lock; set screen security; verify safety numbers with close contacts; review story/privacy settings; keep backups off unless you understand the trade‑offs.

Limits

Requires a phone number identity; push delivery is most reliable with Google Play Services (microG may work; without it, delivery can be less reliable).

Links