Do you have any kind of reference app to show?
Would require more details of app you wish to develop.
So a reference to similar app or design(if-availbale) would be required to help you as per your expectation.
Lets discuss that at chat level, till that time, I'm leaving you with my process. Go through it and let me know.
Onboard 8 years of experienced Android and 6 years of experienced iOS developers who are proficient in Android studio, Java, XML, Kotlin, Objective-C, Swift, XCode, etc for proceeding with your development.
Understand the phases in which your development would be proceeded after you award us:
Phase 1: Focus would be on documentation first for clarity and better understanding from both the sides and come at the same page.
Phase 2: Making of app screens and sharing non-working prototype in an app for both Android and IOS.
Phase 3: Fully functioning. After revisions from Phase 2, we will finish the app and have all testing completed
Phase 4 App Store submission. We are responsible for getting into the app store and published (would need your developer account).
Phase 5: Ongoing bugs and features. We will be available to make fixes as needed for months to come.
Let's chat and discuss more!
Regards,
Sapphire.