First, why encrypted apps?
You shouldn’t have to worry about middlemen accessing your personal conversations. So we look for apps that are end-to-end encrypted and are zero-knowledge based services.
There are a bunch of different encrypted messaging applications that offer good security. Signal is now a well-known end-to-end encrypted messenger. You can have fully encrypted chats and calls. Signal still manages their own servers or at least has opted to use a centralized model for their server architecture.
Moxie Marlinspike of Signal gave a talk explaining why he built Signal with this model in mind. There is merit to what he says, when it comes to upgrading the protocol, but there remains a need for decentralized options.
What tends to be missed is having data and communication redundancies in place for your messaging apps because encryption means nothing if you have no one to speak with.
The past year has shown us that services hosting your data on their servers are security vulnerabilities. From app stores removing applications to hosting providers removing support for specified apps, anyone can see that a need for services that route around these arbiters is greatly needed.
Just recently Facebook and WhatsApp were knocked offline for several hours. Facebook, the seventh largest company on the planet and with a market cap just under a trillion dollars, was inaccessible to its users. It wasn’t possible for you to communicate with anyone through WhatsApp.
Using decentralized tools makes an attack on encryption more difficult.
Now consider this
Imagine if a major cloud provider goes down, or even multiple cloud providers go down at the same time. Are you confident in your current communication stack that you’d be able to communicate with others as if nothing happened?
2020-2021 has shown you that people and entire user-bases can be removed en masse. Let this be a wake up call. Research for yourself and build a communication strategy and stack that you can use comfortably.
You ought to consider self-hosted solutions as well as censorship-resistant routing for your communication protocols. Privacy Tools and Privacy Guides are a good place to start on finding decentralized messaging apps.
Encryption and decentralization are key facets to consider when deciding on which messaging tools to leverage.