Tap the app’s price (or tap Free), then tap Buy to purchase it. If it’s free, tap .
If you see instead of a price, you’ve already purchased the app and you can download it again without charge. While the app is downloading or updating, its icon appears on the Home screen with a progress indicator.
Use a gift card or code. Tap Featured, scroll to the bottom, then tap Redeem.
Send a gift. View the item you want to give, then tap and Gift.
Restrict in-app purchases. Many apps provide extra content or enhancements for a fee. To limit purchases that can be made from within an app, go to Settings > General > Restrictions (make sure Restrictions is enabled), then turn off In-App Purchases. See Restrictions.
Delete an app. Touch and hold the app icon on the Home screen until the icon jiggles, then tap . When you finish, press the Home button. You can’t delete built-in apps. Deleting an app also deletes its data. You can download any app you’ve purchased on the App Store again, free of charge.
For information about erasing all of your apps, data, and settings, see Restart or reset iPhone.