I’m launching a new venture that centres on simple, one-to-one voice calls. Every user will create a profile and attach a single, fixed price per call that is shown up-front to potential callers. When someone taps “Call”, the system should connect the two parties over VoIP, log the transaction, and charge the caller that fixed amount—no per-minute maths, just a clear flat fee. To get there I need the full workflow covered: secure sign-up/login, profile editing with a “price per call” field, in-app balance or card checkout, and a reliable voice stack (Twilio, Agora, WebRTC—whichever you’re most comfortable with). The UX must make price visibility obvious before the call begins, then automatically record that a call happened so the payment can be processed. Key deliverables • Mobile app code (Android and iOS or a single cross-platform build) • Back-end or cloud functions that handle call session creation, real-time status, and payment capture • Simple admin panel to review users, calls, and payouts • Brief technical hand-off notes so I can maintain or scale the service If you’ve shipped VoIP apps or marketplaces with pay-per-interaction models, I’d love to see a quick reference to that work along with your proposed toolset and timeline.