I am looking for an experienced mobile and backend developer to provide a working Minimum Viable Product (MVP) for a VPN service. I need cross-platform mobile apps (Android and iOS) along with a corresponding browser extension. Core Requirements: The Codebase: I am highly open to purchasing and modifying an existing, well-tested white-label VPN codebase to fit my needs. Platform: Android and iOS (Flutter or React Native preferred) + Browser Extension. Monetization: The app will be 100% free for users, monetized entirely through ads (e.g., rewarded ads to unlock connection time). You must integrate a robust ad mediation setup to maximize fill rates and prevent ad limits. Server Architecture: The backend must be extremely cost-efficient. Because the app is free, server costs must correlate strictly with ad revenue. You will need to help set up fast, reliable paid servers that won't drain my budget. Workflow & Terms: Publishing: You only need to deliver the clean, working source code and the backend setup. I will handle all publishing to the App Store, Play Store, and Web Store myself. Post-Launch Support: A mandatory 3-month support and bug-fixing period is required after the final code delivery. To Apply, Please Answer the Following: Can you provide examples of VPN apps or extensions you have previously built or white-labeled? What tech stack do you propose for the app and the backend server management? Which ad networks or mediation platforms do you recommend to avoid ad limits? Do you agree to the 3-month support period after code delivery?