Cross-Platform IoT Control App -- 2

I need an end-to-end mobile application that lets users connect, monitor, and control their IoT-enabled devices directly from a smartphone. The app must run smoothly on both iOS and Android and be built with scalability, security, and performance at its core... (Budget: $750 - $1500 USD, Jobs: Android, Flutter, iOS, iPhone, Mobile App Development, PHP, React Native, User Interface / IA)