When content is loading, a blank or static screen can make it seem like your app is frozen, which may cause people to leave your app.
Make it clear when loading is occurring. Consider showing a spinning activity indicator and descriptive text. For related design guidance, see Activity Indicators.
Show primary content as soon as it's available. Don’t make people wait for all content to load before seeing the screen they're expecting. Use placeholder text and graphics to identify additional content to come. Replace the placeholder elements as content loads. If possible, preload upcoming content in the background, for example, when the user is listening to audio or navigating a menu.