When you develop a mobile-first solution, consider the following mobile app best practices. ## Create responsive designs - The app UI should adjust automatically to fit a smaller mobile screen to ensure a consistent experience on any device. - Prioritize vertical scroll over horizontal scroll, and avoid using any horizontal scrolling elements if possible. ## Ensure core features are available - The core functionality of the app or theme should be available using a mobile device. - Apps should notify users when features are not available on mobile. ## Provide seamless setup - Apps that require theme setup should use [theme app extension](/docs/apps/build/online-store/theme-app-extensions) [app blocks](/docs/apps/build/online-store/theme-app-extensions/configuration#app-blocks-for-themes) and [app embed blocks](/docs/apps/build/online-store/theme-app-extensions/configuration#app-embed-blocks) so that the user doesn’t need to manually make changes to their theme’s code. - Configuration and onboarding should be easy to follow and primarily take place inside the app. - Minimize the number of external web properties users are redirected to post installation.