Signal is a free, privacy-focused messaging and voice talk app that can be used on Apple and Android smartphones, and via desktop). It is an end-to-end encrypted instant messaging and SMS app that allows users to send direct or group messages, photos, and voice messages across multiple devices. Signal uses your phones data connection, so you avoid SMS and MMS fees. Some of its strongest security features include end-to-end encryption, open-source code, and non-profit status. Signal is developed by the non-profit Signal Foundation and its subsidiary, Signal Messenger LLC). Its mobile clients, desktop client, and server are all published under the AGPL-3.0-only license). Signal is a great choice for anyone who values security and privacy, especially journalists who need to keep their sources confidential.