The launch experience has a significant impact on the way people feel about your app. Regardless of the device people are using or how long it's been since they last opened your app, the launch experience should be fast and seamless.
The guidelines below can help you design a delightful launch experience. For developer guidance, see Responding to the Launch of Your App.
Provide a launch screen. The system displays your launch screen the moment your app starts and quickly replaces it with your app's first screen. The function of a launch screen is to give people the impression that your app is fast and responsive, while allowing initial content to load. To ensure a seamless transition from your launch screen, design a plain screen that resembles your first app screen and doesn't draw attention to itself. For guidance, see Launch Screen.
Launch in the appropriate orientation. If your app supports both portrait and landscape modes, it should launch using the device’s current orientation. If your app only runs in one orientation, it should always launch in that orientation and let people rotate the device if necessary. Unless there’s a compelling reason not to, an app in landscape mode should orient itself correctly, regardless of whether the device was rotated left or right. For guidance, see Adaptivity and Layout.
Avoid asking for setup information up front. People expect apps to just work. Design your app for the majority of users and let the few that want a different configuration adjust settings to meet their needs. As much as possible, get setup information from device settings and defaults, or through a synchronization service, such as iCloud. If you must ask for setup information, prompt people to supply it the first time they open the app, and let them modify it later in your app’s settings.
Avoid showing in-app licensing agreements and disclaimers. Let the App Store display agreements and disclaimers so people can read them before downloading your app. If you must include these items within the app, integrate them in a balanced way that doesn’t disrupt the user experience.
Restore the previous state when your app restarts. Don't make people retrace steps to reach their previous location in your app. Preserve and restore your app’s state so they can continue where they left off.
Don’t encourage rebooting. Restarting takes time and makes your app seem unreliable and hard to use. If your app has memory or other issues that make it difficult to run unless the system has just booted, you need to address those issues.
Avoid asking people to rate your app too quickly or too often. Asking for a rating soon after first launch — or too frequently while people are using your app — is annoying and likely to decrease the amount of useful feedback you receive. To encourage well-considered feedback, give people time to form an opinion about your app before asking for a rating. Always provide a way to opt out of rating prompts and never force people to rate your app.