Kangji
About this app
Kangji is a privacy-first personal health record. Photograph a medical test report and AI explains it in plain language; you can then ask follow-up questions in a chat, set medication reminders, and log daily health metrics. Medical photos are stored encrypted on your device and are never persisted on our servers — they pass through a secure cloud endpoint only momentarily for AI analysis. Health Q&A conversations are synced, encrypted, to our cloud so you can restore them across devices.
Privacy Policy
This policy describes what Kangji collects and how we use it.
Data we collect
| Data | Linkage | Used for |
|---|---|---|
| Medical images | Linked to you, stored on device only | Stored in an encrypted SQLCipher database on your iPhone. Transmitted to our Google Cloud Run endpoint only when you tap AI analysis, forwarded transiently to the AI model, and never stored on our servers. |
| AI analysis results (summaries, lab values) | Linked to you, stored on device only | AI-generated text describing your report, stored locally in the encrypted database. |
| Health Q&A chat messages | Linked to you | Your questions and the AI's answers about a report are stored locally AND synced to Firestore (encrypted at rest) so conversations can be restored across devices. |
| Account and device identifiers | Linked to you | A random device ID, and — if you sign in — your Google or Apple account identifier. Used to track your free/purchased analysis balance and keep it across devices. |
| Purchase records | Linked to you | App Store transaction IDs for analysis-credit packs, used to credit your balance and prevent replay. |
| AI usage counts | Linked to you | How many analyses/questions you have run (numbers only — never the content), used for quota and service operations. |
| Anonymous error logs | Not linked to you | PII-redacted error reports to diagnose crashes. |
Third-party services
Kangji relies on these services to function. Each is bound by its own privacy policy.
- Google Cloud Run (kangji-vision-analyze). Receives medical images for AI analysis and forwards them transiently to the AI model — images are never stored. The endpoint verifies requests with Apple App Attest and enforces per-device rate limits.
- Google Gemini API. The AI model that analyzes report images, answers your questions, and generates summaries. We attach no name, email, or demographic data to these requests.
- Firestore (Google Cloud, Tokyo region). Stores your Q&A chat messages (for cross-device restore), analysis-credit balance, purchase records, and usage counts — never your medical images.
- Apple App Store. Processes in-app purchases of analysis-credit packs.
AI processing
Kangji sends some of your content to an AI model for processing. The AI provider receives only the content needed for the task — not your user ID, email, or any other personal identifier. We do not use your content to train any model.
Tracking
Kangji does not track you across other apps or websites. We do not share data with advertising networks, analytics platforms used for cross-app profiling, or data brokers.
Your rights
- Access — request a copy of your data by emailing us.
- Delete — see Delete Account below.
- Correct — edit your profile in the app, or email us for help.
- Object — opt out of optional features in iOS Settings.
Data retention
We retain your data as long as your account exists. After you delete your account, all personal data is permanently removed within 30 days. Anonymous diagnostics may be retained longer in aggregated form.
Children's privacy
Kangji is not directed at children under 13. We do not knowingly collect data from children under 13. If you believe we have, contact us and we will delete it.
Changes to this policy
If we change this policy materially, we will notify you in the app and update the date at the bottom of this page.
Contact about privacy
Email support@cyohei.net with any privacy question.
Terms of Use
By using Kangji, you agree to these terms.
License
cyohei grants you a personal, non-exclusive, non-transferable license to use Kangji on Apple-branded devices that you own or control, per the App Store Terms of Service.
Acceptable use
- Do not reverse engineer, decompile, or attempt to extract source code.
- Do not use the app to violate any law or third-party right.
- Do not abuse the service (e.g. automated scripts hammering the API, attempts to exceed your quota).
- Do not impersonate someone else or misrepresent your identity.
Your content
You retain all rights to content you create in Kangji (recordings, notes, scores, favorites). You grant us a limited license to store and process that content solely to operate the app for you.
Disclaimer of warranties
Kangji is provided as is, without warranties of any kind. We do not guarantee uninterrupted, error-free, or perfectly accurate output (especially AI-generated content).
Limitation of liability
To the maximum extent permitted by law, cyohei is not liable for any indirect, incidental, special, consequential, or punitive damages arising from your use of Kangji.
Governing law
These terms are governed by the laws of Japan, without regard to its conflict of laws principles.
Termination
We may suspend or terminate access if you violate these terms. You may stop using Kangji and delete your account at any time.
In-App Purchase Terms
Kangji offers optional one-time, non-renewing in-app purchases. Once purchased, the unlock is permanent — there is no expiration and you will never be charged again.
Free tier. Every user gets 100 free AI analyses. Follow-up Q&A chat is free (up to 50 questions per conversation).
Available purchases
- Analysis Credits (50) — $3.99 — one-time consumable pack of 50 AI analyses
Billing
Payment is charged to your Apple App Store account at the time of purchase confirmation. This is a one-time charge — not a subscription. There is no auto-renewal and no recurring billing.
Restoring purchases on a new device
Sign in with the same Apple ID and use Restore Purchases in the app to re-download your unlocks at no charge.
Refunds
Refunds are handled by Apple (Apple App Store). Submit a refund request at reportaproblem.apple.com.
Support
Need help? Email support@cyohei.net. We aim to respond within 2 business days.
Before you email
- Make sure you're on the latest version of the app (App Store → your profile → check for updates).
- Try restarting the app and your device.
- If the issue is account-related, include your sign-in email so we can find your account.
Bug reports and feature requests
Email support@cyohei.net with a screenshot or short description. We read every message.
Delete Account
You can permanently delete your Kangji account and all associated data at any time.
From the app
- Open Kangji.
- Go to Settings → Account → Delete Account.
- Confirm. Your account and data are queued for deletion immediately.
From this website
If you cannot reach the in-app option, email support@cyohei.net from the email address registered to your account, with the subject Delete my kangji account. We will verify ownership and delete the account within 7 days.
What gets deleted
- Your Firebase Auth identity (email, sign-in method).
- All your content stored in Firestore and Firebase Storage.
- Purchase records (we keep aggregate financial records as required by law, but they are no longer linked to your identity).
What does not get deleted automatically
- Past Apple purchases — purchases are tied to your Apple ID. To use them again, sign back in with the same Apple ID and tap Restore Purchases.
- Local data on your device — deleting the app from your device removes it.
After 30 days, deletion is permanent and irreversible.