Freemium Mobile App Build

I’m looking to have a polished, security-focused mobile app built and launched as a free download with premium upgrades available through in-app purchases. The same codebase should compile smoothly for both iOS and Android so I can publish simultaneously on the App Store and Google Play... (Budget: $10000 - $20000 CAD, Jobs: AI Development, Android, iOS Development, iPhone, Mobile App Development, Objective C, User Experience Research, User Interface / IA, Web Security)