Bitmessage is described as 'P2P communications protocol used to send encrypted messages to another person or to many subscribers. It is decentralized and trustless, meaning that you need-not inherently trust any entities like root certificate authorities' and is a popular Encrypted Chat app in the file sharing category. There are more than 50 alternatives to Bitmessage for a variety of platforms, including Windows, Linux, Android, Mac and iPhone apps. The best Bitmessage alternative is Signal, which is both free and Open Source. Other great apps like Bitmessage are Element, Tox, SimpleX Chat and Jami.