PETRA Privacy Policy
Effective date: 21 October 2026 · Version: 1.0 · Version française
PETRA – your personal trainer by GYM Blazers ("PETRA", "the app") is published by Winmore Huswiswi Zimmermann (known as Wayne Zimmermann), an individual developer based in the United Kingdom ("I", "me"). This policy explains what happens to your information when you use the PETRA iPhone app and this website. Looking for the rules of use? See the Terms of Use. Need help? See Support.
1. The short version
- No account and no PETRA servers. Everything you enter in PETRA is saved only on your iPhone. I never receive it, can't see it and can't recover it.
- Your health answers stay on your iPhone. PETRA uses them only to keep your workouts safe for you, and only after you agree.
- No ads, no analytics, no tracking, no selling of data. PETRA contains no third-party analytics, advertising or tracking code.
- YouTube videos load only when you tap Play. At that point YouTube (Google) receives some technical data from your device. Nothing you log in PETRA is shared with it.
- You're in control. You can export your data or erase all of it at any time in Profile → Your data.
2. Who is responsible for your data
The data controller for the purposes of the UK GDPR and the EU GDPR (where they apply) is:
Winmore Huswiswi Zimmermann (Wayne Zimmermann)
Email: support@petrapersonaltrainer.fit
"GYM Blazers" is the brand behind PETRA's coaching style and exercise demo videos.
3. What PETRA stores on your iPhone
PETRA stores the following on your device only, in the app's private storage, which iOS encrypts at rest:
| Information | Examples | Why |
|---|---|---|
| Eligibility | Your confirmation that you're 18 or older | PETRA is for adults only |
| Health check answers (health data) | Yes/no answers about heart conditions, chest pain, dizziness or fainting, and whether a doctor has cleared you | To decide whether it's safe to suggest an unsupervised programme, and to suggest checking with a doctor first |
| Assessment and profile | First name or nickname, goal, experience, equipment, time available, limitations or injuries you tell PETRA about (health data) | To build and adapt your plan |
| Workouts and activities | Sessions, sets, reps, timers, breathing sessions, 5K progress, effort and mood ratings, "Stop & Report discomfort" reports and safety pauses (some of this is health data) | To show your progress and adjust your plan safely |
| Walk and run routes | Precise GPS location while a walk or run is being tracked, distance, time and pace | To map your walks and runs |
| Coach chat | Messages you type to PETRA's built-in coach | PETRA answers using fixed rules on your iPhone. Messages are not sent anywhere |
| Consent records | What you agreed to, when, and the version of the wording | To show what you agreed to |
| Preferences | Reminders, voice cues, rest time, your YouTube choice | To remember your settings |
Location. PETRA asks iOS for permission to use your location only while the app is open. Location is used to map walks and runs and, if you use "near me", to find trainers and studios nearby. PETRA does not track you in the background. Tracking pauses if the screen locks or you close the app. You can change this permission at any time in iOS Settings → Privacy & Security → Location Services → PETRA.
Reminders and voice cues. Reminders are local notifications scheduled on your iPhone. Spoken cues use the iPhone's built-in voice. Neither sends data anywhere.
4. Legal basis
Because PETRA processes your information on your own device and I don't receive it, much of this processing happens under your control. To the extent data protection law applies to me as the app's publisher:
- Health data (health check answers, limitations, discomfort reports, effort and mood) is processed on the basis of your explicit consent (UK/EU GDPR Article 9(2)(a) and Article 6(1)(a)). You give it on the "Quick safety check" screen. You can withdraw it at any time with Delete all my data (see section 8). Without these answers PETRA can't check that its workouts are safe for you, so it can't build a plan.
- Other app data (profile, workouts, routes, preferences) is processed to provide the app features you ask for (Article 6(1)(b)). Location is used only after you allow it in iOS.
- Emails you send me are processed to answer you, on the basis of my legitimate interest in providing support (Article 6(1)(f)), or to fulfil my obligations to you (Article 6(1)(b)).
5. What I receive
I do not receive any of the information stored in the app.
I only receive personal data if you contact me (for example by email). In that case I receive your email address, your message and anything you choose to include. Please don't send health details by email. I use this only to reply and to improve PETRA. I keep support emails for up to 24 months after our conversation ends, then delete them, unless I need them longer to deal with a legal claim.
If you've chosen in iOS to share analytics with app developers, Apple may give me anonymised crash reports and aggregated App Store statistics. These don't identify you. You control them in iOS Settings → Privacy & Security → Analytics & Improvements.
6. Third parties
PETRA contains no third-party SDKs (no analytics, advertising, crash-reporting or social-media code). The following parties can still be involved:
- YouTube (Google). Exercise demo videos play from YouTube in its privacy-enhanced mode (youtube-nocookie.com). Before any video or thumbnail loads, PETRA asks you. Once you tap Play, Google receives technical data such as your IP address, device and browser information, and which video you watched. Google may set cookies or similar identifiers. Google acts as an independent controller. See the Google Privacy Policy. If you tap "Open in YouTube", the video opens outside PETRA and YouTube's own terms apply. You can keep videos off: PETRA's written cues guide every exercise.
- Apple. Apple provides iOS, the App Store, Apple Maps and iCloud. When you search "near me", your search words and the map area are sent to Apple Maps to show results. Apple handles App Store downloads and, if you use them, device backups. Apple's use of data is covered by the Apple Privacy Policy.
7. Backups and security
PETRA's data file is protected with iOS Data Protection (encrypted at rest and unreadable until your iPhone has been unlocked after a restart). If you back up your iPhone to iCloud or a computer, PETRA's data is included in that backup so you don't lose your history when you change phones. Those backups are stored under your Apple account or on your computer, not with me. Keep your iPhone protected with a passcode.
8. How long data is kept, and how to delete it
- App data stays on your iPhone until you delete it.
- Profile → Your data → Delete all my data erases everything PETRA saved on the iPhone, including health answers, consents, history, routes, reminders and your YouTube choice. This also withdraws your consent. Withdrawing doesn't affect processing that happened before.
- Deleting the app also removes its data from the iPhone.
- Copies inside older iCloud or computer backups follow your backup settings.
9. Your rights
Under the UK GDPR and the EU GDPR you have the right to access, correct, erase and port your data, to restrict or object to processing, and to withdraw consent at any time.
- For data in the app, you can use these rights yourself, straight away. Export (Profile → Your data → Prepare data export) gives you a copy of everything in a portable JSON file. Delete all my data erases it. You can redo your assessment or edit your preferences to correct it.
- For emails you've sent me, contact me at support@petrapersonaltrainer.fit. I'll reply within one month.
You also have the right to complain to a data protection authority: in the UK the Information Commissioner's Office (ico.org.uk, 0303 123 1113). In France it's the CNIL (cnil.fr). Elsewhere, contact your local authority. I'd appreciate the chance to help first.
10. Automated suggestions
PETRA uses fixed, published rules (not a person) to suggest and adjust your plan, for example making a session easier after a hard one or pausing workouts after you report discomfort. This runs on your iPhone. It's coaching for wellness only and has no legal or similarly significant effect on you. You can always choose a different workout, review a safety pause from the Today tab, or contact me.
11. Children
PETRA is for adults aged 18 or over. It asks your age before you start and doesn't let under-18s continue. I don't knowingly process children's data.
12. International transfers
I don't transfer app data, because I don't receive it. If you play YouTube videos or use Apple services, Google and Apple may process data outside the UK/EEA, including in the United States, under their own safeguards such as the EU–US Data Privacy Framework and its UK Extension, or standard contractual clauses. Support emails are handled with my email provider, which may store data outside the UK/EEA under similar safeguards.
13. This website
This website doesn't use analytics or advertising cookies. The web host may keep standard server logs (such as IP address and pages requested) for security, typically for a short period.
14. Changes
If this policy changes, I'll update the date above and, for important changes, tell you in the app before they take effect. If PETRA ever adds accounts, cloud sync or analytics, this policy will be updated before that version is released.
15. Contact
Questions or requests: support@petrapersonaltrainer.fit