アプリのデザインはシンプルで美しいこと。
（訳注 低俗なアイコンやデザインは禁止）
アプリは更新し続けること。
古くなったアプリはリジェクト
（訳注 アップルにとって都合の悪いアプリはこれを理由に削除されることがあります。）
原文
4. Design
Apple customers place a high value on products that are simple, refined, innovative, and easy to use,
and that’s what we want to see on the App Store.
Coming up with a great design is up to you, but the following are minimum standards for approval to the App Store.
And remember that even after your app has been approved, you should update your app to ensure it remains functional and engaging to new and existing customers.
Apps that stop working or offer a degraded experience may be removed from the App Store at any time.