Can the app design be changed after it launches?

Yes, and how easily depends on what you are changing. Content and layout move without a release; a new screen or a new capability is a release, which means a store review.

Three kinds of change, and what each costs

No release needed

Products, collections, prices, stock, images, discount codes and delivery rates all come from Shopify and are live the moment you change them there. Banners and the order of the home screen’s sections can be moved from a dashboard where the app is built to allow it — which is a decision made at build time and worth asking for.

A release, but a small one

Colours, typography, a new home-screen section built from what already exists. These are an app update: a build, a submission, and a review that usually takes one to three days at Apple and less at Google. Nothing on your side breaks while it is in review — customers keep using the version they have.

A project

A new screen, a new feature, a different navigation model. This is development with its own scope and its own timeline, and pretending otherwise is how a “small change” becomes a three-week surprise.

The decision that matters is made before the build

How much can be changed without a release is set by how the app is built. An app whose home screen is assembled from configurable sections can be rearranged for a season; one whose home screen is hard-coded cannot. Ask about this before you commission, not after — it is the difference between a store that can run a campaign next week and one that files a ticket.