VoIPCall: Open-Source Kotlin Dialer Brings PSTN Calls to Android via Vobiz

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Developer Nuvyntra Labs has released VoIPCall, an open-source native Android dialer built in Kotlin and Jetpack Compose that routes PSTN calls through the Vobiz VoIP platform. The app uses SIP over a secure WebSocket for signaling and WebRTC for audio, supporting Android 12 and later devices. Each device registers a single Vobiz SIP endpoint, with the caller ID tied to a Vobiz number in E.164 format, while authentication credentials are kept in a separate Node.js backend rather than compiled into the APK. Inbound calls can wake the app even when the process has been terminated, using Firebase Cloud Messaging to push notifications to the handset. The project, available on GitHub, serves as a proof-of-concept native client filling a gap left by Vobiz's existing Flutter sample and Java REST SDK, neither of which provided a full Kotlin dialer with WebRTC audio.

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