Signal
A free, open-source messaging app that provides end-to-end encryption for all communications. It is widely recommended by security experts for its strong privacy protections and minimal data collection. Signal is often recommended by privacy advocates and security experts, including Edward Snowden, for its robust security features and commitment to user privacy. It supports text messaging, voice and video calls, group chats, and media sharing. The app is available on iOS, Android, and desktop platforms (Windows, macOS, Linux). Signal uses the Signal Protocol for encryption, which is considered one of the most secure messaging protocols available. The app is developed by the non-profit Signal Foundation, which is dedicated to advancing privacy and freedom of expression through open-source technology.