Android and IOS app development buy and sell app

I am looking for a developer to help me create a buy and sell app for both iOS and Android platforms. I haven't decided yet whether I will need user authentication, so I'm open to exploring different options with the developer. In terms of payment gateway, I am flexible and considering all the options, such as Stripe, PayPal and Google Pay. Ultimately, I'm looking for a dynamic application that is intuitive, user-friendly and able to handle transactions with an efficient payment system. I am excited to find the right person to help me build this app!