CRuler 是一款屏幕测量工具，用于把手机屏幕当作尺子测量小物件尺寸。
我们不收集、不上传、不共享任何个人信息。App 无需注册或登录即可使用全部功能。
界面语言：跟随系统设置自动切换简体中文、香港繁体中文或英文，App 内不提供语言开关； 你也可以在 iOS 设置中为 CRuler 单独指定语言。语言选择本身不涉及任何个人数据，也不会写入 App 的本地存储。
本政策适用于 CRuler iOS 1.0 及后续版本。
CRuler 不收集以下任何信息：
App 内不含任何第三方 SDK（无广告、无统计分析、无社交登录、无崩溃上报）， 也不进行跨 App 或跨网站追踪，不使用 ATT（App Tracking Transparency）。
隐私清单：App 内置 PrivacyInfo.xcprivacy，明确声明不追踪、不收集任何数据类型；
仅因保存本地偏好设置而访问 UserDefaults（Apple 原因代码 CA92.1）。
以下数据保存在 App 的本地存储（UserDefaults 与 App 容器内的 Application Support）中，
不会上传到我们的服务器：
| 数据 | 用途 |
|---|---|
| 主题、配色与弥散光斑布局 | 记住你选的外观 |
| 弥散强度、标尺颜色同步、「跟随滑杆滚动刻度」 | 记住显示与操作偏好 |
| 触感反馈开关、拟物音效开关与音色 | 记住触感 / 音效偏好 |
| 机型校准结果（机型型号、每毫米像素数、长边尺寸） | 保证测量精度 |
| 自定义背景图片与元数据（最多 6 个槽位、每日随机历史、派生配色） | 作为测量界面的背景 |
| 首次启动标记 | 判断是否完成首次引导 |
机型校准会读取设备型号字符串（如 iPhone17,2）、屏幕尺寸与像素密度，
仅在本机用于换算；不读取 IDFA / IDFV，也不会上传。
标记位置、锁定状态与工具栏显隐仅在本次运行内有效，不写入本地存储。 界面语言同样不落盘，只读取系统语言设置。
删除 App 会清除 App 容器内的上述本地数据。iOS 可能按照你的备份设置， 将 App 数据一并纳入 iCloud 或电脑备份；该备份由系统与你管理，开发者无法访问。
App 的「自定义背景」功能使用 iOS 系统提供的 PhotosPicker 选择图片：
App 不收集任何个人信息，因此也不存在针对儿童的专门数据收集行为。
由于我们不收集任何个人数据，也不存在需要导出、更正或删除的服务器端数据。
如需清除全部本地数据，请在 iOS 设置中删除本 App，或使用 App 内的重置功能。 如你开启了 iCloud / 电脑备份，历史备份中的 App 数据可能仍由系统保留，需在备份管理中处理。
若本政策发生变更，我们会在本页面更新「生效日期」，并在重要变更时通过 App 更新说明告知。
你可以在 App 内「设置 → 关于 → 隐私政策」随时打开本政策页面。
如对本政策或隐私保护有任何疑问，请通过 App Store 应用详情页中提供的开发者联系方式与我们联系。
CRuler is a screen measuring tool that turns your phone's screen into a ruler for measuring small objects.
We do not collect, upload, or share any personal information. Every feature is available without registration or sign-in.
Language: the app follows your system language and switches automatically between Simplified Chinese, Hong Kong Traditional Chinese, and English. There is no in-app language switch; you may also set a language for CRuler in iOS Settings. Your language choice involves no personal data and is not written to the app's local storage.
This policy applies to CRuler for iOS 1.0 and later versions.
CRuler does not collect any of the following:
The app contains no third-party SDKs (no advertising, analytics, social login, or crash reporting), and it does not track you across apps or websites. It does not use ATT (App Tracking Transparency).
Privacy manifest: the app bundles PrivacyInfo.xcprivacy, which declares no tracking
and no collected data types. The only accessed-API declaration is UserDefaults (Apple reason CA92.1),
used solely to remember local preferences.
The following data is stored in the app's local storage (UserDefaults and Application Support
inside the app container) and is never uploaded to our servers:
| Data | Purpose |
|---|---|
| Theme, colors, and diffuse-blob layout | Remember your appearance choice |
| Diffuse intensity, ruler color sync, and "Scroll with slider" | Remember display and interaction preferences |
| Haptics toggle, sound toggle, and sound choice | Remember haptic and sound preferences |
| Device calibration results (model, pixels per millimeter, long-edge size) | Ensure measurement accuracy |
| Custom background images and metadata (up to 6 slots, daily-random history, derived palette) | Serve as the measuring interface background |
| First-launch flag | Determine whether onboarding is complete |
Device calibration reads the device model string (for example iPhone17,2), screen size, and pixel
density, and uses them only on-device for conversion. It does not read IDFA / IDFV and never uploads them.
Marker positions, lock state, and toolbar visibility are valid only for the current session and are not written to local storage. The interface language is not stored either; only the system language setting is read.
Deleting the app removes this local data from the app container. iOS may include app data in your iCloud or computer backups according to your backup settings; those backups are managed by the system and by you, and the developer cannot access them.
The "Custom Background" feature uses the system PhotosPicker provided by iOS to select images:
The app collects no personal information, so there is no child-specific data collection.
Because we collect no personal data, there is no server-side data to export, correct, or delete.
To erase all local data, delete the app in iOS Settings or use the reset function inside the app. If you have iCloud or computer backups enabled, app data in historical backups may still be retained by the system; manage that through your backup settings.
If this policy changes, we will update the "Effective date" on this page and notify you through the app's release notes for material changes.
You can open this policy at any time in the app via Settings → About → Privacy Policy.
If you have any questions about this policy or about privacy protection, please contact us using the developer contact information provided on the App Store product page.