KilterFit is a logbook for people who already train. It keeps your training, meals, and weight on your device. A few things leave it (only with your action), and this page is the full picture of what those are.
The short version
- We never sell your data. We never run ads.
- There is no KilterFit account. Your workouts, meals, and weight live on your device.
- Photos and descriptions you send to log a meal are processed by our nutrition API and not retained on our servers after the response.
- Apple Health access is opt-in. Saved meals mirror back to Health so your other Apple devices see the same totals.
- AI Coach is off by default. When it's on, it prefers on-device Apple Intelligence and only falls back to our server when on-device isn't available.
No account
KilterFit does not ask you to create an account. There is no email signup, no profile, no password to manage. The app does not collect your name, address, phone number, or demographics.
What stays on your device
Workouts, meals (including the photos you attach to a saved meal), weight entries, and your settings live in this device's Application Support folder. They do not sync to a KilterFit server. Deleting an entry in the app deletes it from disk immediately. There is no sync queue and nothing tombstoned for later.
What leaves your device
Meal photos and descriptions (nutrition API)
When you log a meal by photo or by typing a description, that photo or text posts to KilterFit's nutrition API for analysis. The response (calories, macros, detected items, a confidence score) comes back to your device, where you decide whether to save it. Images sent for analysis are not retained on our servers after the response. If you save the meal, the image is stored locally with the entry, on your device only.
Server-side request logs record metadata only: a timestamp, request ID, the resulting status code, response duration, the number of detected items, and which model providers ran. Logs never include your image, your description, or the model's output.
AI Coach
AI Coach is off by default. With it off, the Coach tab uses local calculations only. Nothing leaves your device. With it on:
- If your device supports Apple Intelligence and you've enabled "Prefer Apple Intelligence", coach reports are generated on-device using Apple's Foundation Models. Your data does not leave the device for these reports.
- Otherwise, a small snapshot of the metrics needed to compose a report (a summary derived from the Apple Health tier listed below, plus your training and nutrition totals for the period) is sent to KilterFit's coach API. The summary is used to generate the report and is not retained after the response.
Apple Health values that feed the coach snapshot when AI Coach is on and the server path is used: resting heart rate, HRV, sleep, steps, weight, blood pressure, lean body mass, body fat percentage, height, active and basal energy, exercise minutes, VO2 max, flights climbed, walking heart-rate average, blood oxygen, and sleeping wrist temperature. They flow into the prompt; they are not rendered on the Vitals card and are not stored on our servers.
Apple Health (HealthKit)
KilterFit asks for HealthKit permission so it can show your vitals on the Vitals card (resting HR, HRV, sleep, steps, weight, blood pressure) and so saved meals can mirror back to Health. Reads happen on-device. Writes are limited to nutrition entries you save, which are written to Health so your other Apple devices show the same totals. Weight and workouts you log in KilterFit stay on this device and are not written to Health.
You can revoke HealthKit access at any time in iOS Settings → Privacy & Security → Health → KilterFit.
Diagnostics (Sentry)
Crash and performance diagnostics flow to Sentry so we can keep the app stable. These reports do not include workout, meal, or health data. They contain technical context (device model, OS version, app version, stack traces) and are governed by Sentry's privacy terms.
Third-party processors
To estimate nutrition from a photo or description, KilterFit's API forwards the request to third-party AI model providers. Each provider receives only the photo and/or description for the specific request, never your Apple Health data, your meals, your workouts, or any persistent identifier. We work with providers under contracts that prohibit training on the data we send and require zero retention of request payloads where the platform supports it. The specific provider lineup may change over time as models improve; material changes will be reflected in this policy.
We also use a hosting provider to run the API, Sentry for diagnostics, and USDA FoodData Central (a public US government nutrient database) for branded-item lookups; the USDA service receives only the query string for a lookup, never any identifier.
Subscriptions
Pro purchases are handled by the App Store. Apple charges your account; we receive an entitlement signal that unlocks Pro features. KilterFit never receives your billing details (payment method, billing address, Apple ID email) and stores only the entitlement state needed to gate features.
What we don't do
- We do not sell your data, ever.
- We do not share your data with advertisers, data brokers, insurers, or employers.
- We do not run third-party advertising or behavioral tracking SDKs.
- We do not retain raw meal photos on our servers after the request completes.
- We do not store your HealthKit data on our servers as persistent records.
- We do not require an account, an email address, or a phone number.
Retention
- Meal photos and descriptions sent for analysis: not stored on our servers after the request returns.
- Coach snapshots sent to the server path: used to generate the report; not retained afterward.
- Server logs (metadata only): retained for up to 30 days for debugging and abuse detection.
- On-device data (workouts, meals, weight, settings): retained until you delete it.
Your choices
- Revoke HealthKit access in iOS Settings.
- Turn AI Coach off in Settings (it's off by default).
- Prefer Apple Intelligence (on-device) for AI Coach in Settings.
- Skip photo logging: use the text input only, or skip nutrition logging entirely.
- Delete any individual entry in the app (workout, meal, weight) and it's gone immediately.
- Delete the app from your device to remove all local data. Meals previously mirrored to Apple Health remain in Health until you remove them there.
Children
KilterFit is not intended for users under 13. We do not knowingly collect data from children under 13.
Security
Traffic between the app and our API is TLS-encrypted. We follow least-privilege access for internal systems. No system is perfectly secure; if you spot something, please email us.
Changes to this policy
We'll update this page when meaningful things change: new processors, new categories of data, new retention windows. The "Effective" date at the top reflects the latest version. Material changes will be surfaced in the app before they take effect.
Contact
Questions, data requests, or feedback: support@kilterfit.mozmail.com.