Mobile app for transportation

I am looking for a mobile app developer to create an application for both iOS and Android platforms. The purpose of this app is to provide a convenient transportation solution for users. This app will require user accounts for login and authentication, and will need to be connected to the internet for proper functioning. The developer will be responsible for creating the necessary code to make this app come to life. All design requirements such as colors, fonts, layout have already be planned and put together. The app has already has already begun to be created but I'm looking for a dedicated app developer to finish it off. The developer should have prior experience in app development, and be knowledgeable in coding the desired functionality. The timeline for the project is three weeks. This project requires very close collaboration between myself, the developer, and any other necessary personnel involved in the project. Additionally, I will need assurance that the app meets all requirements.