"Many developers will not want to change the way they are building apps, merely to provide responsive design. To accommodate this choice, App Inventor includes a screen property called Screen.Sizing. Screen.Sizing can be set to either fixed or responsive. When sizing is fixed, App Inventor creates apps for a screen of size 320 pixels wide and 460 pixels high, but it scales the app’s appearance to match the actual size of the screen that the app is running on. This display is essentially equivalent to how App Inventor apps were rendered on Tablets prior to App Inventor version 145."