nSplit Privacy Policy
nSplit is a personal running coach for iPhone and Apple Watch. Your training data stays on your iPhone. It leaves the phone only when the AI coach needs it to answer you, and only after you have allowed it. We do not sell data, show ads or track you across apps and websites.
1. Who is responsible
The controller under the EU General Data Protection Regulation (GDPR) is:
Vladimir Klementev
[POSTAL ADDRESS]
Email: privacy@nsplit.app
Write to this address for any question about your data or to exercise your rights.
2. Data on your iPhone
With your permission, nSplit reads from Apple Health: running workouts (time, distance, duration, elevation, indoor or outdoor, weather recorded by the watch, laps and workout steps), heart rate and resting heart rate, distance and step samples, workout effort ratings, the altitude profile of workout routes, and your date of birth. Your date of birth is used once to estimate your maximum heart rate and is not stored. Latitude and longitude of your routes are not stored by nSplit.
nSplit also stores on your iPhone what you enter or create in the app: your goal and schedule, heart-rate zones, your training plan, check-ins about how you feel (including pain and illness signals and short notes), chats with the coach, notes the coach keeps about you, the coach's analyses, and a record of the AI requests made (task, token counts, estimated cost). Your own Anthropic API key, if you use one, is kept in the iOS Keychain.
This data stays on your device and in your own device backups. We have no access to it. Health data is never used for advertising or marketing.
If a workout has no time-zone information, nSplit asks Apple Maps for the time zone of the workout's first route point. Only that single point is sent to Apple for this lookup.
3. The AI coach
The coach is Claude, an AI model made by Anthropic, PBC (USA). To build and adjust your plan, analyse your runs and answer in chat, nSplit sends the model the information it needs:
- workouts: date and local time, distance, duration, pace, heart rate and time in heart-rate zones, cadence, elevation, temperature and humidity, splits, effort ratings;
- your heart-rate zones, resting and maximum heart rate (maximum heart rate may be estimated from your age), goal, schedule, and the reasons and constraints you entered;
- check-ins about how you feel, the coach's notes about you, and your chat messages.
Not sent: your name, Apple ID, contacts, date of birth, or route coordinates.
The coach is used only after you allow it on the “What the coach sees” screen. You can withdraw this consent at any time in Settings › Privacy › Share data with the coach. Your data then stays on your phone and the coach stops responding.
How requests travel depends on how you use the coach:
- With your own Anthropic API key: requests go directly from your iPhone to Anthropic under your own agreement with Anthropic. They do not pass through our servers.
- With an nSplit subscription: requests go through the nSplit server in Germany, which forwards them to Anthropic using our account. The server does not write the content of requests or answers to disk. To deliver an answer again after a dropped connection, it keeps finished answers in memory for at most 5 minutes. Anthropic receives no identifier of you from us.
Under its commercial terms, Anthropic does not use data sent through its API to train its models and keeps it only for a limited period for its own safety and legal purposes. See Anthropic's privacy policy. Anthropic is located in the USA; the transfer is covered by the safeguards in Anthropic's data processing terms (EU Standard Contractual Clauses).
AI answers can be wrong. The coach is not a doctor and its advice is not medical advice.
4. Subscriptions
Purchases are made and paid through Apple. We never see your payment details, name or Apple ID. To check that your subscription is active and to protect it from misuse, the nSplit server stores:
- subscription information signed by Apple: original transaction ID, product, plan, status, purchase and expiry dates, and the App Store environment;
- the time zone of your device, so that your weekly limits reset on your Monday;
- for each of your devices: a device key created by Apple's App Attest service (a public key and Apple's attestation) and the app transaction ID, to keep a subscription on at most 5 devices in 30 days and to block modified apps;
- a usage journal of AI requests: task type, model, token counts, cost, and time, to enforce your weekly limits and to investigate disputes.
- your weekly limit balances and the record that you already received the free first plan, stored under a pseudonym (a keyed code derived from your transaction ID) so that limits keep working.
These records are linked to your subscription's original transaction ID, not to your name.
5. Usage statistics
To understand which features help runners and where the app needs work, nSplit sends pseudonymous usage events (they carry no name or account, only a random installation ID) to our server, for example “a plan was built”, “a run was analysed”, “the paywall was shown”, an onboarding step, or the duration of a background analysis in coarse ranges. Each event carries only fixed values from a predefined list, the app version, platform, a coarse language setting, and a random installation ID that is not derived from anything else and changes when you reinstall the app. Times are rounded to the hour or the day.
No run data such as routes, distances, pace or heart rate, no messages and no names are sent. The server does not store your IP address with these events and does not link them to your subscription. Events are kept for 13 months and are not included in backups.
You can turn statistics off at any time in Settings › Privacy › Share anonymous usage statistics. The app then sends one last event saying that statistics were turned off, and nothing after that.
6. Server logs and backups
The nSplit server runs at Hetzner Online GmbH in Falkenstein, Germany. Its web server keeps technical access logs (time, address requested, status) without IP addresses for 30 days. Error logs may contain the IP address of a request that failed while the service was unavailable; they are kept for 30 days. Aggregated service metrics without personal data are kept for 90 days.
To protect the service from overload, the server uses the network part of your IP address for a few minutes in memory to limit request rates. It is not stored.
The server database is backed up every night, encrypted, to Hetzner storage in Germany. Backups are kept for at most 3 months. Usage statistics are not backed up.
7. Legal bases
- Providing the coach and your subscription: performance of our contract with you (Art. 6(1)(b) GDPR).
- Sending health-related data to the AI coach: your explicit consent (Art. 9(2)(a) and Art. 6(1)(a) GDPR), which you can withdraw at any time without affecting earlier processing.
- Protecting subscriptions from misuse (device keys, limits, usage journal) and keeping the service secure and running (logs, backups): our legitimate interests (Art. 6(1)(f) GDPR).
- Usage statistics: our legitimate interest in improving the app (Art. 6(1)(f) GDPR); you can object at any time by turning statistics off.
8. Recipients
- Anthropic, PBC (USA) — processes coach requests (section 3).
- Hetzner Online GmbH (Germany) — hosts our server and backups as our processor.
- Apple — processes purchases, App Attest, Apple Health, Apple Maps and the App Store under its own privacy policy.
We do not sell or share your data with anyone else.
9. How long we keep data
| Data | Kept |
|---|---|
| Data on your iPhone | until you delete it or the app |
| Coach answers in server memory | at most 5 minutes |
| Subscription information | 12 months after the subscription ends |
| Device keys | 60 days after their last use |
| Device list (pseudonymous) | 30 days after the device was last used |
| Weekly limit balances (pseudonymous) | 35 days after the week ends |
| Free first plan marker (pseudonymous) | without time limit, so it is granted once |
| Usage journal | about 13 months |
| Usage statistics | up to 14 months |
| Record of a deletion request (pseudonymous) | 6 to 12 months |
| Server logs | 30 days |
| Backups | at most 3 months |
10. Deleting your data
Settings › Privacy › Delete my data deletes everything nSplit stores on your iPhone and, if you use a subscription, the records about you on the nSplit server: your subscription information, and the transaction details on your device list. The usage journal is anonymized (kept without any link to you) for billing audits. Your usage statistics from this installation are deleted too.
So that deleting data cannot be used to reset limits or obtain the free first plan again, the server keeps under a pseudonym only what those limits need: weekly balances, the device list without transaction details, device keys (a public key and Apple's attestation, with no subscription ID — kept so your phone keeps its place), the free-plan marker, and a record that you asked for deletion. The record stops Apple's renewal notices from recreating your subscription information until you use the subscription again. None of this contains your name, and it can be linked to you only by someone who has both our secret key and your transaction ID. These items are deleted on the schedule in section 9.
Copies in backups disappear within 3 months; if a backup is ever restored, earlier deletions are applied again. If your subscription has already ended, the app cannot reach your server records — write to privacy@nsplit.app, or they are deleted automatically after the periods in section 9.
Deleting your data does not cancel your subscription — manage it in the App Store. Data in Apple Health belongs to you and Apple and is not touched.
11. Your rights
You have the right to access your data, to have it corrected or erased, to restrict its processing, to data portability, and to object to processing based on legitimate interests. You can withdraw consent at any time. Most of your data is on your device and under your control. For data on our server, write to privacy@nsplit.app. You also have the right to lodge a complaint with a data protection supervisory authority, in particular in the EU member state where you live.
12. Age
nSplit is intended for people aged 16 and over.
13. Security
All connections are encrypted (TLS). API keys and device keys are kept in the iOS Keychain. Backups are encrypted. Access to the server is limited to the operator.
14. Changes
We will update this policy when the app changes how it handles data. The date at the top shows the latest version. Significant changes will be announced in the app.