Mobile app

I am looking for an experienced mobile app developer to create a custom app for both iOS and Android. This app will be for my start-up messaging service. Primarily, I would like payment integration included in the app, such as Stripe or any other payment gateway option you suggest. Additionally, the app should be developed for both iOS and Android platforms, and be aesthetically appealing and user-friendly so customers have a great experience. Finally, it would be helpful if you have expertise in chat functionality, social media integration, and commerce. If these features or other features you suggest could be added to the mobile app, that would be a major plus.