官网有很多新功能发布会并没有提及的 iOS 15 新功能，其中不乏我认为值得被提及的好功能

https://www.apple.com/ios/ios-15-preview/features/

这里是 iOS 15 的更新内容列表，我觉得里面有很多功能非常实用，足以让我期待全新版本。

Custom email domain

Personalize your iCloud Mail address with a custom domain name, and invite family members to use the same domain with their iCloud Mail accounts.

iCloud+ 用户可以使用由苹果托管的域名邮箱了。

Built-in authenticator

Generate verification codes needed for additional sign-in security. If a site offers two-factor authentication, you can set up verification codes under Passwords in Settings — no need to download an additional app. Once set up, verification codes autofill when you sign in to the site.

系统内置了 2FA 的应用，可以不用第三方 App 了。

Temporary iCloud storage to transfer your data

Now when you buy a new device you can use iCloud Backup to move your data to your new device, even if you’re low on storage. iCloud will grant you as much storage as you need to complete a temporary backup, free of charge, for up to three weeks. This allows you to get all your apps, data, and settings onto your device automatically.

提供免费的临时 iCloud 空间以备份传输数据到新设备上。