This guide covers the required build assets when packaging your app for delivery as a binary package with AppGyver Composer.
The app icon is shown on the device's home screen, in different parts of iOS and in App Store.
You can read more about app icons in Apple's App Icon documentation.
The launch screen (sometimes called splashscreen) is a full-screen image that appears immediately when your app starts up. It is Apple's intention that the launch screen helps make your app feel fast and responsive. As such, it should represent static parts of your app's initial UI, so that when the app actually launches, the transition will be seamless. That said, many apps show a logo or similar on the launch screen.
Composer only supports static PNG images for the launch screen. This means a separate image is required for all supported screen sizes.
You can read more about the launch screen and view a list of required screen sizes in Apple's Launch Screen documentation.