Adding sound shouldn’t be an issue at all.
Experience-wise, my last project consisted of developing an e-commerce platform consisting of 3 apps. One was for the client including location, QR code scanning for orders management, distance calculation, product listing, product filtering, order coordination and much more. notifications history…etc. The second is the backoffice for shops as well as admins to post products, make (timed if desired) promotions, statistics and more, the final app was the deliveryman’s and it essentially just receives orders and directs the deliverymen.
These included 3 apps and 2 web apps all 5 of them were made with flutter, so either flutter for android and flutter web.
So I’m confident I can make something you’ll like.