Hello. I can advise you to order not only the android app, but also the iOS app. Because this way it will be much more popular and you won't have to overpay by much. The position you can order from fintech mobile app development company
https://surf.dev/mobile-app-development-estimation/ . This company for developing any application in the fluter engine has a lot of experience in this field, so you can fully trust them and not even watch the development process.