Authentication

Ask users to authenticate only in exchange for value, such as personalizing the experience, accessing additional features, purchasing content, or synchronizing data. If your app requires authentication, keep the sign-in process quick, easy, and unobtrusive, so it doesn’t detract from the enjoyment of your app.

只有在交换价值才要求用户认证，例如个性化的体验，访问额外特性，购买内容，或者同步数据。如果你的app要求认证，保持登录迅速、容易、不唐突，这样才不会降低你的app愉悦感。

Delay sign-in as long as possible.People often abandon apps when they are forced to sign in before doing anything useful. Give them a chance to fall in love with your app before making a commitment to it. In a shopping app, let people browse your merchandise immediately upon launch and require sign-in only when they're ready to make a purchase. In a media streaming app, let people explore your content and see what you have to offer before signing in to play something.

尽量延迟登录。用户通常放弃app因为他们在完成任何有用的事前被要求登录。给他们一个机会去爱上你的app在他们需要作出承诺之前，一开始让人们浏览你的商品，只要在他们准备好购买时才要求登录。在一个流媒体应用，首先让用户探索你的内容，看看你提供了什么，然后再登录做其他事情。

Explain the benefits of authentication and how to sign up for your service.If your app requires authentication, display a brief, friendly explanation on the login screen that describes the reasons for the requirement and its benefits. Also, remember that not everyone using your app has an account from the start. Make sure you explain how to get one, or provide a simple in-app way to sign up.

解释认证的好处和怎么注册你的服务。如果你的app要求认证，展示一个简短的、友好的解释在登录界面，描述登录的原因及好处。同时，记住不是所有人在开始用你的app有一个账户。确保你有解释怎么得到一个账户，或者在app里提供一个简单的注册途径。

Minimize data entry by showing appropriate keyboards.When asking for an email address, for example, show the email keyboard screen, which includes helpful data entry shortcuts.

通过显示合适的键盘简化数据输入。当询问一个email地址，例如，显示email键盘屏幕，这个键盘包括有用的数据输入捷径。