Hotels Booking App

i am looking to develop app for iOS and android (react or flutter) which will be very simple and easy Ui to use for customers, We have our multiple hotel properties which we want to make app for, App should have modern and interactive easy to use interface, mockup designs will provided.
a complete backend dashboard will be needed to manage all hotel bookings from one place.
all standard hotel booking app and push notifications features should be there in application.