Messenger is described as 'Offers group video calls, voice calls, and instant messaging with photo sharing, real-time notifications, and location mapping for seamless connectivity' and is a very popular instant messenger in the social & communications category. There are more than 100 alternatives to Messenger for a variety of platforms, including Android, iPhone, Windows, iPad and Mac apps. The best Messenger alternative is Signal, which is both free and Open Source. Other great apps like Messenger are Telegram, Element, Discord and Pidgin.