In the App Builder section of Shopify you can configure your preferred colors, images, and style of the mobile app. From here you can also select which collections or products to showcase on the homepage and decide how to arrange your catalogue.
In the subsection Homepage you can select which widgets to display in the first view shown to the user.
In the subsection Catalogue Menu you can select and exhibit the collections that are shown in the application catalogue.
In the Style subsection you can select the app colors and images that best suit your brand.
In the Layouts subsection you can customize the layout of the main views of your Shoppy app.