E commerce app

I am looking to develop an e-commerce app that is compatible with both the Android and iOS platforms. For this project, I require user authentication and a payment gateway to be integrated as well. I have all the feature requirements in mind along with other specific details. I am hoping to find a Freelancer to help me create this application, who has experience with developing mobile apps for different types of stores and other e-commerce platforms. This should be someone who has a strong understanding of programming languages such as Swift, Objective-C and Java, as well as experience with other tools, technologies and frameworks. The ideal Freelancer should be able to develop the app from start to finish and make sure all the requirements are met.