Android Voice Call App

I’m building a straightforward voice-only calling app dedicated to Android. The core requirement is rock-solid one-to-one voice communication, so there’s no video feed or chat module to worry about—just clean, low-latency audio calls... (Budget: ₹12500 - ₹37500 INR, Jobs: Android, Android App Development, Java, Kotlin, Mobile App Development, Mobile Development, SIP, WebRTC)