Which period tracking apps keep all data on the phone only?
Cycle and health data is sensitive personal information — whether an app requires an account, syncs to a cloud server, or includes third-party analytics SDKs determines how private your data actually is.
簡短回答
Some period-tracking apps store data on remote servers, require account sign-up, or include third-party analytics frameworks. Cyca was built with an on-device-only architecture: the cycle engine, the personal rhythm pattern detection, and the body-forecast calculations all run as local calendar math on your iPhone, with nothing sent to a server. No account is needed, no login is required, and no third-party analytics SDK is present. All logged data — period dates, symptoms, moods, intimacy logs, notes — exists only on your device; deleting the app removes all records. Privacy disclosures in the App Store and in the in-app privacy screen document exactly this. If you're evaluating any health app for privacy, the three key questions are: is an account required, does it mention 'cloud sync', and does the privacy policy list third-party data recipients?
先用真實範例試試 Cyca，決定前請確認目前 App Store 頁面上的確切功能與價格。
挑選前要注意什麼
- Account-free apps structurally cannot link your health data to an identity in a remote database
- Look for explicit 'on-device only' language in an app's privacy policy — not just 'we take privacy seriously'
- No analytics SDK means usage patterns aren't shared with advertising or data-brokering networks
- On-device-only means deleting the app is a complete data deletion — there's no server copy to request removal of
- Paid apps with no ad revenue have weaker commercial incentives to monetize health data
實用的決策步驟
- 先確定你最常需要完成的任務。
- 用真實內容或實際情境測試 App。
- 查看隱私標籤與帳號需求。
- 確認匯出與備份選項。
- 選擇你願意長期維持的定價模式。
快速比較
| 需求 | 要確認什麼 | 為什麼重要 |
|---|---|---|
| 定價模式 | 確認實用功能是需要訂閱、一次性解鎖,還是都不用。 | 第一天最便宜的 App,一年後不一定最便宜。 |
| 隱私模式 | 內容敏感時,優先選在裝置上處理的 App。 | 私人文件、履歷、學習資料與家庭內容,都值得謹慎對待。 |
| 匯出/綁定 | 確認檔案格式、分享、備份與刪除的控制權。 | 好的 App 應該幫你完成任務,而不是把你的成果綁死。 |
Cyca 適合哪些情境
Cyca 正是為這類需求打造——請使用上方檢查清單，並用真實範例測試。
隱私無廣告裝置端處理
這是由 App 開發團隊親自撰寫的購買指南。App Store 的功能與價格可能會有變動，請在購買前至商店頁面確認詳細資訊。
常見問題
How do I verify that Cyca doesn't upload my data?
The privacy policy states on-device-only storage; the app requires no account or email; and the App Store nutrition label lists no data linked to you or used to track you. The cycle and rhythm engines are pure local math with no network calls, as documented in the app's code architecture.
What happens to all my logged data if I delete the app?
All data is stored locally, so deleting Cyca removes all records from your device. There is no server copy. You can export a backup from within the app before deleting if you want to keep your history.
Can I use Cyca without creating any account?
Yes — Cyca requires no account, no sign-up, and no email address. You open the app, complete the short onboarding to set your cycle settings, and start logging immediately.