Berty
Berty is a secure peer-to-peer messaging app
... developers could access your data, let alone corporations or governments. Just like blockchain technologies, Berty doesn’t pass your data through central servers - the place where internet service providers, hackers, and governments can intercept your data. Instead, Berty’s network is distributed, based on P2P direct messaging. Berty couldn’t care less about who you are. You don’t need to provide your real name, an email, or a date of birth. You don’t even need a SIM card!