Mobile apps
Messaging App
End-to-end encrypted chat clients. Look for a published threat model, reproducible builds, and metadata minimisation (no phone-number requirement is a strong plus).
Session
Messaging App
Onion-routed messenger with no phone number or email — accounts are random IDs and metadata is minimised.
Signal
Messaging App
End-to-end encrypted messenger with a strong privacy reputation; open-source clients and server.
SimpleX
Messaging App
Decentralised messenger with no user IDs or phone numbers — connection profiles only.
