Messaging apps are essential for personal and professional communication in California. WhatsApp, with 2.7 billion global users, is popular for its free messaging, voice, and video calling, especially among immigrants due to its end-to-end encryption. Telegram has 950 million monthly active users and is favored for its security features, large group chats, and file-sharing capabilities; it is also used by online casino gamers for anonymous gaming and integrated bots. iMessage, with 1.3 billion global users, is preferred by Apple users for its seamless integration and security features. Facebook Messenger has over 1 billion users and is widely used for casual conversations and customer service, aided by automated chatbots and payment functionalities. Signal, with over 40 million monthly active users, is chosen for its strong privacy features, appealing to journalists and activists.