Background calling, Bluetooth audio routing, and adaptive network switching between Wi-Fi and cellular. The same VoiceTel SIP credentials follow you between devices.
Native iOS client with CallKit-style call presentation, background incoming-call wakeup, and Bluetooth audio routing across AirPods, in-car systems, and wired headsets. Adaptive transport falls back gracefully between Wi-Fi and cellular.
Native Android client with foreground-service-backed background calling, full Bluetooth headset and in-car audio support, and seamless network switching between Wi-Fi and mobile data.