Privacy Policy

Mattronica LLC · Last updated November 2, 2026

This policy covers King’s Gym Trainer, an iPhone app published by Mattronica LLC for members of King’s Athletic Club. The short version: you don’t give us your name, email or any account details. Your workouts live on your phone, with an anonymous backup on our server. When you ask Rey, the app’s coach, for a plan, your answers and a summary of your training are sent to Anthropic, whose AI writes the plan.

On your phone

• Your workouts. Each workout, the plan day, how you felt (full, lighter or short), and for every set the exercise, the weight and reps, and the time you ticked it.
• Your plan, and your answers to Rey’s questions, so you can start from them next time.
• Climb to King. Your card for the month is worked out on your phone from your workouts. If a club-wide comparison is ever added, it will be opt-in and will show only card levels and counts, never names.
• The club’s equipment list, downloaded from our server, so the app works without a signal.

Backup on our server

To keep your history safe if you replace or reset your phone, the app sets up an anonymous member on our server the first time it backs up. It keeps a random key in your phone’s Keychain; our server stores only a one-way fingerprint of that key, and no name, email, phone number or device identifier. The server, run by Mattronica LLC on Cloudflare, stores:

• Each finished workout: the club, the plan day, how you felt, and when it started and finished.
• Each set in it: the exercise, the planned and logged weight and reps, and when you ticked it.
• Plans you ask Rey for (their name, Rey’s note and the exercises), and which one you chose.

We use this to restore your history to a new phone, and to give Rey your recent training and your pace (how long your sets and moves between exercises take) when you ask for a plan. Your answers to Rey’s questions are not stored on our server.

Rey and Anthropic

Rey’s plans are written by Claude, an AI model from Anthropic. Only when you ask Rey to build or change a plan, our server sends Anthropic:

• Your answers: your goal, days a week, time per workout, lifting experience, anything you type about what to avoid, and anything else you tell Rey, such as other sports you play or something you’re training for.
• A summary of your last eight weeks of backed-up training (for each exercise: how many sessions, the last date and the heaviest weight) and your pace.
• The club’s equipment list and, when you ask for a change, the draft plan and what you asked for.

It never sends your name, contact details or any device identifier. Anything you type about an injury or health condition is health information: it’s optional, so share only what you’re comfortable with. Anthropic processes this to write your plan under its commercial terms, which do not allow it to train its models on this data. See Anthropic’s privacy policy.

Network and abuse limits

• Our servers run on Cloudflare, which sees your device’s IP address when the app connects, as with any internet service.
• To stop abuse, when a phone first sets up a backup we keep a one-way fingerprint of its network address combined with the date, and delete it after a day. We also count each member’s requests to Rey per day.

Usage statistics

To learn which features members use, the app sends anonymous usage statistics to Aptabase, a privacy-focused analytics service. You can turn this off at any time in the app under Privacy & analytics, at the bottom of the main screen.

• What is sent: the name of an action (for example “workout finished” or “exercise swapped”), counts and choices (for example how many sets were ticked, how long a workout took, which plan day or check-in was chosen, which of the club’s exercises was swapped to, and whether the free-text boxes were filled in), the time, a random session number that is kept only in memory and resets when the app restarts, your operating system and its version, and the app version.
• What is never sent: anything you type (including your answers to Rey and anything about injuries), the weights you lift, your workout history or plan, your name or contact details, or any advertising or device identifier.
• No profiles: the statistics cannot be linked to you or your device, and are not sold or used for advertising.

What we don’t do

• No advertising, no tracking across apps or websites, and we never sell your data.
• The app doesn’t ask for your location, camera, microphone, contacts or the Health app.

Keeping and deleting your data

Backups are kept while you use the app, so a new phone can restore them. To delete your data, open Privacy & analytics at the bottom of the app’s main screen and tap Delete my data. It deletes your workouts, plans and anonymous member from our server, then everything the app keeps about you on your phone. Deleting the app removes what’s on your phone but leaves the backup, so a reinstall can restore it. If you’ve lost the phone, email us and we’ll find your backup from the dates and times of a few of your workouts. Usage statistics can’t be deleted, because they can’t be linked to you.

Data stored on your phone may also be included in your iCloud backups, under Apple’s terms.

Children

King’s Gym Trainer is not directed to children under 13, and we do not knowingly collect personal information from them.

Changes

If this policy changes, the updated version will be posted here with a new date.

Contact

Questions about privacy: hello@kingsgymtrainer.com.