Trainbook Privacy Policy
Trainbook is a home training log with an optional AI Assistant (also shown in the app as "Sports Assistant"). It runs on iPhone, iPad, Mac, and Apple Watch. Trainbook is developed and operated by Xiaofeng Liu, an individual developer ("we", "us"). This policy explains what we collect, why, who we share it with, how long we keep it, and how you can delete it.
1. Data we collect
| Category | What |
|---|---|
| Account | Email address, display name, password (stored only as a salted hash), account time zone. |
| Profile | Optional: gender, height, birth year, self-rated training level, strength training history, typical weekly cardio, injury or movement limitations and notes, training preferences, AI Assistant persona and preference text, weight unit, Perfect Day goal, and card layout. |
| Training | Workouts (activity type, date, duration, distance, calories, heart rate), strength sessions (exercises, sets, weights, reps, times, notes), plans, programs and recurring plans, and the equipment you mark as available. |
| Apple Health data | Only the types you allow: weight, sleep, Activity Rings (active energy, exercise minutes, stand hours), steps, heart rate, and workouts from Apple Watch, Fitness+, and the Workout app. Values are saved to your account when the app writes a log. Live heart rate during a session stays with that session. |
| AI Assistant | Your chat messages, the AI's replies, daily suggestions, workout and plan summaries, and usage counters used for the weekly AI quota (feature, time, token counts). |
| Your own AI provider (optional) | If you add your own AI provider, its address, model name, and API key. The key is encrypted (AES-256-GCM) and is never shown back. |
| Subscription (optional) | If you subscribe to Trainbook Plus, the App Store transaction details Apple sends us: product, original transaction ID, purchase and expiry dates, and renewal or refund status. Apple handles payment; we never see your card. |
| Devices and sign-in | Per-device access keys and sign-in sessions (stored as hashes), and when they were last used. |
| Technical | Standard server logs (such as IP address, time, and request path) used for security, rate limiting, and troubleshooting. |
We do not use advertising identifiers, analytics SDKs, or third-party tracking. We do not collect precise location, contacts, photos, or payment card data.
2. How we use it
- To run the app: show your Today, Records, and Plans, sync between your devices, and keep your training history.
- To power the AI Assistant, but only after you allow AI data sharing (see section 4).
- To keep the service secure and working: authentication, rate limiting, abuse prevention, and fixing problems.
We do not sell your personal data. We do not share it for cross-context behavioral advertising. We do not use Apple Health data for advertising, marketing, or data mining, and we never sell it.
3. Apple Health (HealthKit)
Trainbook reads only the Health data types you approve in the Apple Health permission sheet. It writes weight you enter, and workouts recorded by Trainbook on Apple Watch, back to Apple Health. You can change these permissions at any time in the Health app or in Settings. Data stored in Apple Health is controlled by you and Apple. Deleting your Trainbook account does not delete it; manage it in the Health app.
4. AI Assistant and third-party AI providers
The AI Assistant uses a large language model run by a third-party AI provider. Before anything is sent, the app asks for your permission, and nothing goes to an AI provider until you tap Allow. You can turn this off at any time in Settings → AI Assistant. When it is off, the server refuses every AI request, and proactive suggestions stop.
When AI data sharing is on, an AI request can include your profile (for example training level, limitations, and injury notes), recent training, plans, and Apple Health-derived data such as sleep, weight, Activity Rings, and heart rate, plus your chat messages. We send only what the request needs.
Providers we use:
- DeepSeek: the default provider. DeepSeek is based in China, and data sent to it may be processed on servers outside the United States, including in China.
- OpenRouter: a backup routing service. It forwards requests to the underlying model provider when the default is unavailable.
- Your own provider: if you add your own provider in Settings, your AI requests go to that provider instead, under its own terms and privacy policy.
Data sent to an AI provider is subject to that provider's retention practices. We do not control what a provider keeps.
When the app uses the AI Assistant without a Trainbook account, the server keeps only the App Store app-transaction id, token hashes, the time you allowed AI data sharing, subscription state, and AI usage counts. It does not store prompts, replies, or training data.
Not medical advice. Trainbook is a training log and does not provide medical advice. The AI Assistant gives general training guidance only. It is not a doctor, does not diagnose or treat any condition, and is not a substitute for professional medical advice. Talk to a qualified professional before starting a new program and about any injury, pain, or health condition. Stop exercising and get help if you feel pain, dizziness, or shortness of breath.
5. Where data is stored and who we share it with
Your account data is stored on servers we run on Oracle Cloud Infrastructure in the US West region. Data in transit is protected with TLS. We share personal data only:
- with our hosting provider (Oracle Cloud), which stores it for us;
- with AI providers as described in section 4, only after you allow it;
- when required by law, or to protect the safety, rights, or property of users or others.
Some data also stays on your devices so the app can work offline: cached pages, unsynced training sessions, and your sign-in key in the device Keychain.
6. How long we keep it
We keep your data while your account exists. AI usage records are deleted after 365 days at the latest. Database backups are kept for up to 30 days and then rotate out.
7. Deleting your account
In the app, go to Settings → About → Delete Account, re-enter your password, and confirm. Deletion is immediate and permanent. Your account, profile, training, body data, plans, AI chat history, your own AI provider key, and all device sign-ins are erased from our live database right away. There is no undo.
- Copies in database backups may remain for up to 30 days until those backups rotate out. Backups are not used for anything else.
- Data already sent to an AI provider is subject to that provider's retention.
- Data in Apple Health is not affected.
If you cannot sign in (for example, you forgot your password), email support@xinwon.com from the address on the account and we will delete it for you.
8. Your choices and rights
- View and edit your profile and training data in the app.
- Turn AI data sharing on or off in Settings → AI Assistant.
- Change Apple Health permissions in the Health app or Settings.
- Delete your account at any time (section 7).
- Ask us for a copy of your data, or ask any privacy question, at support@xinwon.com.
US state privacy rights. Depending on where you live (for example California, Washington, or Nevada), you may have rights to know, access, correct, or delete your personal data, including consumer health data, and to withdraw consent. We collect health data only to provide the app, share it with AI providers only with your consent, and never sell it. To use any of these rights, email support@xinwon.com. We will not treat you differently for doing so.
9. Children
Trainbook is not directed to children under 13, and you must be at least 13 to create an account. If we learn that a child under 13 has created an account, we will delete it. Parents can contact us at support@xinwon.com.
10. Security
We use TLS in transit, salted password hashing, hashed access keys, and AES-256-GCM encryption for stored AI provider keys. No system is perfectly secure, but we work to protect your data and limit who can access it.
11. Changes
If we change this policy, we will update the effective date above. If a change is material, for example a new AI provider or a new use of your data, we will tell you in the app before it applies.
12. Contact
Xiaofeng Liu (Trainbook) · support@xinwon.com