Develop an app

I am looking for an experienced developer to create an e-commerce app for both iOS and Android. I have a rough idea of how I would like the design to look, but need help finalizing it. My main focus for the app is on usability and user experience. The app must be intuitive, easy to navigate, have a well-designed user interface, and be compatible with various devices. I am open to hearing suggestions from the developer. Other requirements include the ability to securely process payments, the deployment of the app on both the App Store and Google Play, and providing technical support post-launch.