Privacy Policy

TautFit is a training app for iPhone and Apple Watch. It is operated by Qi Design Studios Pte Ltd, 60 Paya Lebar Road, #06-28 Paya Lebar Square, Singapore 409051 (“we”, “us”). This policy explains exactly what the app collects, where it goes, and what control you have over it. It is written to be read, not to be survived.

1. What we collect

Stored on your device

TautFit is local-first. Everything you log is written to a database on your iPhone and the app works fully offline. This includes your sessions and the sets, reps, weights, RPE, distances, durations and notes inside them; the exercises and nicknames you have taught it; your body measurements; goals; injury and constraint flags; programs; and your app settings.

If you never sign in, that is where it stops. Nothing on this list leaves your phone except through Apple's own iPhone backup, if you have iCloud Backup enabled, or a CSV file you export yourself.

Sent to our server if you sign in

Signing in is optional and is only required for cross-device sync, for a Pro subscription, and for the coach after your first few messages. When you sign in with Apple we receive and store:

• Your Apple user identifier — an opaque string Apple generates for TautFit specifically. It is not your Apple ID and cannot be used to identify you outside this app.
• Your email address, as released by Apple. If you chose “Hide My Email”, we only ever see Apple's relay address, not your real one.
• Your training data, as encrypted-in-transit rows in our sync database, so a second device can pull the same history. This mirrors the on-device list above.
• Subscription state — whether you have an active Pro subscription and when it expires, derived from Apple's own signed receipts. We never see your payment method, card details, or billing address; those stay with Apple.
• Usage counters — how many coach messages and AI resolutions you have used this week, so free-tier limits can be enforced. These are counts, not content.
• Bug reports, if you submit one from inside the app — the text you wrote, plus your user identifier so we can reply or credit you.

What we do not collect

We have no advertising identifiers, no third-party analytics or attribution SDKs, no location tracking, and no crash-reporting service that ships your data to a vendor. We do not track you across apps or websites, and we do not build a profile of you for any purpose other than running the features you are using.

2. Apple Health data

Health access is entirely optional and you can revoke it at any time in iOS Settings.

• We read your body weight, and your workouts recorded by Apple Watch or other apps, so that runs and activities you have already tracked appear in TautFit without you logging them twice.
• We write the gym sessions you complete in TautFit back to Apple Health, so your Activity rings and other apps stay accurate.
• Heart rate is read live during a session on Apple Watch to display it while you train.

Imported workouts become normal session entries, which means they are covered by the sync described above if you are signed in. If you would rather Health data never leave your phone, do not sign in, or turn off Health import in the app's Health settings.

3. The AI coach

Three features send text to our server, which runs a language model on Cloudflare Workers AI:

• Coach chat — your message, plus a summary of your recent training so the answer is about you rather than generic advice.
• Free-form exercise resolution — the phrase you typed, when it cannot be matched on your device. The result is cached so the same phrase never needs sending again.
• Program design — a summary of your history, to build a plan.

We do not store your coach conversations on our server, and the model provider does not use this input to train models. Resolved exercise phrases are cached so the app gets faster and cheaper with use. The numbers you log are never sent to a language model for interpretation — weights and reps are parsed by a deterministic grammar on your device, precisely so a model can never invent one.

4. Why we process it

5. Who we share it with

We do not sell your data and we have no advertising partners. Data reaches exactly three other parties, each doing a job we could not do ourselves:

• Apple — operates the App Store, Sign in with Apple, subscription billing, and Apple Health. Apple handles all payment information; we never see it.
• Cloudflare — hosts our server, our sync database, and the AI model that answers coach questions. They process data on our instructions as our infrastructure provider.
• Law enforcement or regulators, only where we are legally compelled, and only to the extent required.

6. How long we keep it

• On your phone — until you delete it or remove the app.
• On our server — while your account exists. Deleting your account purges your synced rows, account record, and subscription record.
• Usage counters — expire automatically within weeks; they exist only to enforce the current period's limits.
• Bug reports — up to one year, then they expire automatically.

7. Your rights and controls

Regardless of where you live, TautFit gives you these directly in the app:

• Export — Settings has a CSV export of every set you have logged, in a format any other app or spreadsheet can read.
• Delete your account — Settings → Account. This erases your synced data and account record from our server. Data on your phone is removed by deleting the app.
• Revoke Health access — iOS Settings → Privacy & Security → Health → TautFit, at any time, with no effect on the rest of the app.
• Use the app without an account — sign-in is only needed for sync, Pro, and extended coach use.

If you are in the UK, EU, or a similar jurisdiction, you also have the right to access, correct, port, restrict, or object to our processing of your data, and to complain to your local data protection authority. If you are a California resident, you have the right to know, delete, correct, and to opt out of “sale” or “sharing” — we do neither, so there is nothing to opt out of. Write to privacy@tautfit.com and we will respond within 30 days.

8. Security

All traffic between the app and our server uses TLS. Your identity is verified against Apple's published signing keys on every request, and subscription receipts are verified against Apple's certificate chain rather than trusted as sent. Sync data is stored in a database that partitions rows by account, and is only readable with a valid session for that account. No system is perfectly secure, but if a breach affects your data we will tell you and the relevant regulator as required by law.

9. Children

TautFit is not directed at children under 13, and we do not knowingly collect data from them. If you believe a child has provided us with data, contact us and we will delete it.

10. International transfers

Our infrastructure runs on Cloudflare's global network, so your data may be processed in countries other than your own, including the United States. Where required, these transfers rely on Standard Contractual Clauses or an equivalent safeguard.

11. Changes

If we change this policy we will update the date at the top, and for material changes we will tell you in the app before the change takes effect. We will never retroactively broaden how we use data you have already given us without asking you first.

12. Contact

privacy@tautfit.com
Qi Design Studios Pte Ltd
60 Paya Lebar Road, #06-28 Paya Lebar Square,
Singapore 409051