Android app (useing flutter) like job portal

Hi, I need help creating an Android app using Flutter. I am not in need of a built-in payment system as I have that covered. Unfortunately, this question was skipped however, any suggestions for UI/UX design would be appreciated. This app is for an online store, so the design needs to be sleek and professional. I am open to suggestions and valuable feedback from the development team. Please let me know if you have the experience necessary to help with this project. Thank you.