Once your app is on the App Store, you can edit certain attributes associated with your app without going through the review process. To edit attributes associated with your app, go to the Manage Your Applications page in iTunes Connect and click Edit Information. Within this section, you can modify the following:
Large app icon and screenshots
Application URL, support URL and support email address
Editing Attributes While You Have an Update in Review. Before you make changes to attributes that are associated with an existing app, it's important to consider the impact it will have on your app if you have an update that is in review:
Availability date. If you change your app's Availability Date to a date in the future while you have an update to your app in review, your app will be removed from the App Store until the new date approaches. This is because the availability date is not tied to a version; the availability date applies to the application as a whole.
Price tier. If you edit your price tier for a version of your app that is in review, the price change will be applied to your currently live app, because price tier is not tied to a version.
In all cases where you are updating attributes, ensure you carefully review the changes you make as they will not be reviewed by Apple. Your updates will be reflected within 24 hours after they are submitted.