DailyDiff.

Privacy Policy

Last updated: June 15, 2026

DailyDiff (“we”, “us”, the “App”) is an English vocabulary learning app. We keep data collection to the minimum needed to run the service. This policy explains what we collect, why, and the choices you have.

Information we collect

  • Anonymous device identifier. When you first open the App, it generates a random device ID stored on your device. We use it to deliver the daily puzzle, keep your free daily allowance, and prevent abuse. It is not your Apple ID and does not identify you personally.
  • Apple account (optional). If you choose Sign in with Apple, we receive an opaque Apple user identifier (and a relay email only if you choose to share one). We never receive your Apple password.
  • Your submissions. The answers you write are sent to our server and to an AI model to generate scoring and feedback.
  • Purchases. Subscriptions are processed by Apple. We receive transaction identifiers from Apple to unlock Pro features. We never receive your payment card details.
  • Device integrity (App Attest). For anonymous scoring we use Apple’s App Attest to confirm the request comes from a genuine app on a real device. This produces a cryptographic key and counter — no personal data.
  • Technical data. Your IP address and basic request logs are processed transiently for security and rate limiting.

How we use your information

  • Provide the daily puzzle, AI scoring, history, and streaks.
  • Manage your subscription and entitlements.
  • Prevent abuse, fraud, and excessive automated requests.
  • Maintain and improve the service.

AI scoring and service providers

To score your answers, the text you submit is sent to a third-party AI model provider (Anthropic) through our backend. We share only what is needed to provide the service, and we do not use your submissions to advertise to you. Our service providers include:

  • Apple — Sign in with Apple, In-App Purchases, App Attest.
  • Cloudflare — hosting, database, and image storage.
  • Anthropic — AI model that generates your feedback.

Sharing

We do not sell your personal information and do not share it for advertising. We disclose data only to the service providers above, or where required by law.

Retention and your choices

  • Delete your account. In the App, go to Profile → Delete Account. This permanently removes your server-side account and associated data.
  • Local data. Your attempt history is stored on your device; deleting the App removes it.
  • We retain data only as long as needed to provide the service or meet legal obligations.

Children

DailyDiff is not directed to children under 13 (or the minimum age in your region), and we do not knowingly collect their personal information.

Security & international processing

Data is processed on Cloudflare’s global infrastructure and protected with industry-standard safeguards. No method of transmission or storage is completely secure, but we work to protect your information.

Changes

We may update this policy from time to time. Material changes will be reflected by the “Last updated” date above.

Contact

Questions? Email support@dailydiff.vip.

隐私政策

最后更新：2026 年 6 月 15 日

DailyDiff（“我们”“本应用”）是一款英语近义词辨析学习应用。我们仅收集运行服务所必需的最少数据。本政策说明我们收集什么、为什么收集，以及你拥有的选择。

我们收集的信息

  • 匿名设备标识。首次打开应用时，会在你设备本地生成一个随机设备 ID，用于下发每日题目、记录免费额度、防止滥用。它不是你的 Apple ID，也不能识别你的真实身份。
  • Apple 账号（可选）。若你选择「通过 Apple 登录」，我们会收到一个不透明的 Apple 用户标识（以及仅在你选择分享时提供的中转邮箱）。我们永远不会获得你的 Apple 密码。
  • 你提交的内容。你写下的作答会发送到我们的服务器和 AI 模型，用于生成评分与点评。
  • 购买信息。订阅由 Apple 处理，我们从 Apple 收到交易标识以解锁 Pro 功能；我们永远不会接触你的银行卡信息。
  • 设备完整性（App Attest）。匿名评分时，我们使用 Apple 的 App Attest 验证请求来自真实设备上的正版应用。它仅产生一个加密密钥与计数器，不含个人数据。
  • 技术数据。你的 IP 地址与基础请求日志会被临时处理，用于安全与限流。

我们如何使用这些信息

  • 提供每日题目、AI 评分、历史记录与连续打卡。
  • 管理你的订阅与权益。
  • 防止滥用、欺诈与过量的自动化请求。
  • 维护并改进服务。

AI 评分与服务提供方

为给你的作答评分，你提交的文本会经由我们的后端发送给第三方 AI 模型提供方（Anthropic）。我们只共享提供服务所必需的内容，且不会用你的作答向你投放广告。我们的服务提供方包括：

  • Apple —— 通过 Apple 登录、应用内购买、App Attest。
  • Cloudflare —— 托管、数据库与图片存储。
  • Anthropic —— 生成点评的 AI 模型。

共享

我们不出售你的个人信息，也不会为广告目的共享。除上述服务提供方外，仅在法律要求时才会披露。

保留与你的选择

  • 删除账号。在应用内进入「我的 → 删除账号」，即可永久删除你在服务端的账号及相关数据。
  • 本地数据。你的作答历史存储在设备本地，删除应用即可清除。
  • 我们仅在提供服务或履行法律义务所需的期限内保留数据。

儿童

DailyDiff 不面向 13 岁以下（或你所在地区的最低年龄）儿童，我们不会在知情情况下收集其个人信息。

安全与跨境处理

数据在 Cloudflare 的全球基础设施上处理，并采用行业标准的保护措施。没有任何传输或存储方式是绝对安全的，但我们会尽力保护你的信息。

政策变更

我们可能不时更新本政策。重大变更将通过上方的「最后更新」日期体现。

联系我们

有疑问？请邮件至 support@dailydiff.vip。