Mobile app for fitness startup

I'm looking for a talented mobile app developer to create an app for a fitness startup. The app should be built for both iOS and Android platforms with a key feature of a workout tracker. I have an overall idea in mind, however I need help in terms of professional input to bring the idea to life. The successful freelancer must have relevant experience and expertise in order to make this project a success. If you believe you can help me create the perfect app, please reach out. Thanks! At her is the design style I’m going for. Basic black and white. Neat and professional