A glossy Matrix chat client — secure, decentralized messaging with end-to-end encryption by default.
Federated messenger client. Encryption is default; data stays on your chosen homeserver. Optional analytics are opt-in and disabled by default.
Element (formerly Riot.im) is the flagship client for the Matrix decentralised communication network. You can chat with anyone on any Matrix server — your homeserver can be self-hosted, an existing account on matrix.org, or a paid Element-hosted one. End-to-end encryption is on by default with cross-signed device verification. Rooms can be joined across servers, bridging connects to IRC, Slack, Telegram and more, and voice/video calls work 1:1 or in groups. The app is open source (Apache-2.0). Identity data, message history and keys stay under the control of whatever server you choose.
Element by Element (Vector Creations) — Communication app, 32 MB, requires Android 6.0+. Direct APK download on AppsDone, scanned for malware.