K9 Chat is an End-To-End Encrypted, "Zero Trust" based chat application with secure voice and video calls, providing anonymous communications with no tracking possibility - Only usable with K9 servers - on-premise, cloud-based or hybrid over VPN maintaining the most possible level of security in communications within entities, governments and closed teams.
Features:
- End-to-end encrypted messaging
- Secure 1:1 and group voice calls
- Secure 1:1 and group video calls
- Encrypted file sharing
- Static location attachments
Foreground service usage (Android policy disclosure):
During an active voice or video call, K9 Chat runs a phone-call foreground service to keep the WebRTC audio session alive when you switch apps or lock your screen. Without this service, Android would suspend the call activity within ~30 seconds and the call would drop. The service is:
- User-initiated: only starts when you place or accept a call.
- User-visible: shows a persistent "Ongoing call" notification while the call is active.
- User-stoppable: ending or declining the call stops the service immediately.
The service declares android:foregroundServiceType="phoneCall", matching the FOREGROUND_SERVICE_PHONE_CALL permission used for VoIP and telecom-style calling apps.
Contact: support@k9.ms
Latest Version
3.3.16Uploaded by
Alexandre GF
Requires Android
Android 7.0+
Category
Free Communication AppContent Rating
Everyone
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Flag as inappropriateLast updated on Sep 28, 2026
Fixes push notifications and incoming call ringing.
The app was registering for notifications against the wrong Firebase project, so every notification the server sent was rejected and never reached the device.
