Privacy Policy

1.Our core principle: local-first

Persto has no fitness-data backend. We operate no server that receives, stores or processes your fitness data, and the app makes no request to any Persto system. The following are held in the app's private storage on your device. Your display name and coach voice can also be copied to your iCloud account only when you use the manual save control described in section 7.

• Body metrics you enter (height, weight, age, biological sex, used for a calorie estimate)
• Legacy allergy information from an older beta, if it still exists; the current Apple app does not ask for or use it and provides an in-app removal control
• Workouts, sets, reps, personal records, your chain and your achievements
• Your goal, experience level, split, available equipment, schedule and wake time
• The readiness verdicts the app has computed, and the reasons behind them
• Your conversations with the coach, and the notes it keeps about what you have told it
• Health and fitness data you choose to connect (see §3)

If you connect a compatible Garmin watch, Persto also keeps the selected Garmin device's opaque identifier, friendly name and model, plus pending workout messages, in protected local storage on your iPhone. The Garmin watch keeps the workout plan and unsynchronized session facts until the phone acknowledges them or you erase them from the watch when no workout data is waiting.

The protected health and training store is excluded from device cloud backups. Deleting the app removes that local iPhone store. It does not remove workouts already written to Apple Health, a setup copy you manually saved to iCloud, an encrypted export you placed elsewhere, the Persto app installed on a Garmin watch, or activities already stored by Garmin.

Small non-health app preferences may use iOS standard preferences storage and may be included in a device backup. These include display-unit choices and dismissed hints. The app's privacy manifest declares that storage category and its permitted purpose. Measured health data, body metrics, workouts and training history stay in the protected, backup-excluded app store described above.

2.What Constantia receives from the app

The app has no Persto accounts, no user profiles on our side, no advertising identifiers and no analytics or tracking SDKs. The optional Garmin connection includes Garmin's official Connect IQ companion SDK for device selection and direct iPhone-to-watch messaging. Persto does not use that SDK for advertising, analytics, attribution or tracking. The core training experience works signed out and without an internet connection. Network-dependent actions are limited to Apple's App Store services for subscriptions, the manual iCloud setup controls, optional Sign in with Apple, a direct transfer you start over the local network, Garmin device setup and a Garmin activity synchronization that you control through Garmin. None of those sends your fitness data to Constantia Technologies servers.

3.Apple Health and fitness data

With your explicit permission, Persto reads the following from Apple Health on your iPhone. Sleep, resting heart rate and heart rate variability can affect the readiness verdict. The other readings provide descriptive workout, activity, body-composition and cardiovascular-fitness context:

• Sleep analysis, resting heart rate and heart rate variability (the three readings the readiness verdict is built from)
• Respiratory rate and VO2 max, when Apple Health has them, as descriptive cardiovascular-fitness trends; they do not change the readiness verdict
• Steps, active energy burned, Apple Exercise Time and workouts
• Body mass, body fat percentage and lean body mass, for weight and body composition trends
• Workout routes, so an outdoor workout can be drawn on a map

Persto asks for the narrowest set that answers a question it actually asks. Each category above is used in the app's recovery, fitness, body-composition, activity or workout views. A missing reading is shown as missing rather than replaced with a guess.

With your permission the iPhone app writes only workouts you explicitly finish or choose to save, including an ended-early partial session. It deliberately does not write a calorie figure, because the phone does not measure calories and an estimate saved into your health record would be indistinguishable from a measurement.

On Apple Watch, a session that is running reads your heart rate, active energy and distance from the watch sensors so it can show live effort and pace. When you finish or explicitly save a Watch workout, the watch writes that workout to Apple Health. An outdoor run, walk, hike or ride may also include its measured route, active energy, distance and climb.

You grant each permission individually and can revoke any of them at any time in Apple Health under Sharing. Apple deliberately does not tell an app when read access has been refused, so Persto treats missing data and refused data identically: it says the reading is not there rather than substituting a number. This data is used on your Apple devices only. Raw Apple Health records and readings are not sent to Constantia Technologies or Garmin, are not sold, and are never used for advertising. A workout plan computed on your iPhone can reflect your readiness and can be sent to a watch only after you choose that watch for the workout.

3a.Location

The iPhone app never asks for location access and cannot read your location. Routes shown on the map come from workouts already stored in Apple Health, are drawn on screen, and are not copied into Persto's own storage.

The Apple Watch app asks for location only when you start an outdoor run, walk, hike or ride, and uses it only while that session is running, so the workout can be saved to Apple Health with its real route, distance and pace. The route goes into your health record. Persto does not keep its own copy, does not read it back on the watch, and does not send it anywhere. The watch also uses its altimeter, with your permission, to measure climb.

4.The Apple Watch app

Persto on Apple Watch starts and runs a session from your wrist. The watch and the phone exchange data directly over their paired connection, which does not pass through any server of ours. The watch sends the phone what you did, and the phone sends the watch what to show today. A watch face complication can show today's state.

4a.Garmin watches and Garmin Connect

The Garmin connection is optional. Persto sends a workout only after you choose Garmin + iPhone. Garmin Connect handles compatible-device selection, pairing and installation of the Persto watch app. Persto never asks for or receives your Garmin password.

Garmin's official iPhone companion SDK moves the selected workout and its controls directly between the iPhone and watch over their companion connection. The iPhone can send the workout title, exercises, sets, rep or time targets, rest times and short form cues. The watch can return the session identifier, timestamps, progress, completed or skipped sets, reps, weight, set effort, duration, skip reason and whether Garmin reported a successful save or discard. Constantia Technologies does not operate a server that relays or stores these messages.

The Garmin app reads current heart rate from the watch sensor while a workout is active so it can show that reading on the watch. Persto does not send those live heart-rate samples back to the iPhone or separately store them in its Garmin message journal. If you save the activity, Garmin's activity system may include sensor data in the saved activity.

You can choose End and save or End without saving. A saved activity remains on the Garmin device and may synchronize to Garmin Connect according to your Garmin account and device settings. That Garmin activity is separate from Persto's workout history on iPhone and is handled under Garmin's privacy terms. The current Garmin app does not request GPS or route access.

The current integration does not import your Garmin Connect health history or prior activities and does not use Garmin's cloud Health, Activity, Training or Courses APIs. Garmin Connect is used for device setup and watch-app installation, plus any activity synchronization Garmin performs after you save an activity. Workout control messages travel directly between the selected devices.

Data you enter into Persto is provided to Constantia Technologies LLC as Persto's developer. Garmin is not responsible for Persto's handling of that data. When you choose Garmin + iPhone, the workout information described here is transmitted to your selected Garmin device using Garmin software. A saved activity may later synchronize to Garmin Connect under your Garmin settings and Garmin's privacy terms.

Forget Garmin devices removes Persto's selected-device record and pending iPhone messages. It does not uninstall the Persto watch app or delete activities already stored by Garmin. You can remove those separately through Garmin's apps and device controls.

5.The on-device coach

The optional coach conversation runs on Apple's on-device foundation model, on your iPhone. Your question, the numbers it is answered from and the reply are all processed on the device. The prompt and reply are not sent to us or to a Persto cloud coach. Once Apple's on-device model is available, the coach can work without an internet connection.

The coach keeps notes on your device about things you tell it, so it can remember them next time, along with the history of your conversation. Both live in the app's private storage with everything else and are removed when you delete the app. You can clear them in the app.

The model may phrase an answer. It never decides your training: what you are asked to do is produced by deterministic code, and the coach cannot change your plan or your measurements. If it thinks a setting should change, it asks you.

6.Sign in with Apple

Persto has no account system. Sign in with Apple is optional and is used for one purpose: if the sending phone is signed in when you hand data to another iPhone, the receiving phone must present the matching app-specific Apple identifier before it can apply the transfer. Persto keeps that identifier on the device for the comparison. We do not receive your password, name or email address, and nothing about the sign-in reaches us.

7.Manual iCloud setup copy

Persto does not automatically sync setup changes. If you tap Save preferences to iCloud, Persto stores one encrypted setup payload in your iCloud key-value store. It seals the payload with AES-256-GCM before it enters iCloud and keeps the separate random key in your synchronizable iCloud Keychain. We have no access to either one because they are in your Apple account, not ours.

The copy contains only the display name you use in Persto and your chosen coach voice. It contains no training level, split, place, equipment, schedule, goals, workout length, wake settings, Health readings, body measurements, allergies, readiness history, training history or exercise log. Those categories are excluded by name in the code and covered by tests.

You choose when to save and when to restore. Both controls are free. The in-app Delete saved preferences from iCloud control removes the encrypted payload, its separate key and any legacy Persto beta record without deleting anything on this iPhone. See delete your data for every deletion route.

8.Moving to a new iPhone

Persto can hand everything, including your health-derived history, straight to your other iPhone over the local network. It never goes to a server and is never written to a file you have to look after.

The transfer is sealed with AES-256-GCM under a key derived from a one-time 16-character code shown on one device and typed on the other. Each phone requests available device authentication before the transfer. If the sender used Sign in with Apple, the receiver must use the matching app-specific Apple identifier. The connection is torn down when the transfer finishes.

You can also export the same data as an encrypted file, protected by a passphrase you choose. The passphrase never leaves your device, so if you lose it the file cannot be recovered by anyone, including us.

9.Device authentication

You can ask Persto to require the device's available authentication before it opens, so your training history is not on show when somebody else is holding your unlocked phone. Authentication may use Face ID, Touch ID or the device passcode as supported by iOS and your settings. Persto is told only whether the check passed and never sees biometric data.

10.Persto Plus

Persto Plus is an auto-renewing subscription sold by Apple. Your purchase is tied to your Apple Account and is verified on your device. We operate no subscription server, receive no receipt, and are not told who subscribed. We see only the anonymous, aggregated sales reporting Apple provides to every developer, which contains no personal information. Payment details are handled by Apple and never reach us.

11.Background activity

With your permission Persto asks iOS to wake it briefly when a new workout is added to Apple Health, and schedules occasional background refreshes, so what you see is current when you open it. This happens on your device. Nothing is transmitted to Constantia Technologies.

12.This website

The website is separate from the app. Using it creates no account and puts nothing on your phone.

Early access list. If you submit your email address through the early access form, we store that address and the date you submitted it, so we can tell you when there is something to try. That is the only reason it is kept. It is not used for marketing, not added to any newsletter, and not shared or sold. Signups are deleted when early access ends.

Feedback form. If you report a bug, we store what you typed, along with anything you optionally added: your email address, your phone model and the app version. Every field except the message is optional, and a report with no address is still accepted. The report is filed as a ticket in the project's private issue tracker, hosted by GitHub, so it sits next to the code it is about. That tracker is not public. The form sends only what you type into it. It has no access to the app and cannot read your workouts or health data, so please do not paste anything into it that you would not want stored in a ticket.

To stop either form being abused, we count recent submissions per network address for one hour. The network address is stored hashed, never in the clear, in a throwaway counter that holds no email address and is not linked back to your submission.

Ask us to delete anything you sent, at any time, by emailing support@perstofitness.com.

13.What we do NOT do

• No advertising, and no advertising identifiers.
• No analytics, tracking, advertising or crash-reporting SDKs. Garmin's companion SDK is used only for the optional Garmin device connection described in section 4a.
• We do not track you across other apps or websites, and the app does not contain the framework that would let it.
• We do not sell your personal information or share it for advertising or tracking. Data moves to Apple, iCloud or Garmin only through the user-controlled features described in this policy.
• Health data is never used for advertising. Persto never writes Apple Health data to the app's iCloud setup store or sends raw Apple Health records to Garmin.
• A Garmin activity leaves the watch only according to the Garmin synchronization settings you control. Persto does not copy Garmin activity or health history into Apple Health.

14.Your choices and data deletion

• Local app data: delete the app from iPhone Storage or the Home Screen. The shipping app does not claim to have a single in-app erase-all control, and there is no server-side fitness-data copy to ask us about.
• Health permissions: manage or revoke per type in Apple Health under Sharing.
• Garmin connection: use Forget Garmin devices in Persto to clear the selected-device record and pending iPhone messages. Uninstall the Persto watch app and delete saved Garmin activities separately through Garmin's apps or device controls.
• Manual iCloud preferences copy: use Delete saved preferences from iCloud in Persto. Full detail is on the delete your data page.
• Subscription: manage or cancel in your Apple Account settings. We cannot cancel it for you, and cancelling never removes your local data.

15.Data security

Local data, including the Garmin selected-device record and pending-message journal, is kept in app-private, sandboxed storage, written with iOS Data Protection at the until-first-unlock class so approved background work still functions after a restart, and marked to stay out of device cloud backups. Encrypted exports and direct transfers use AES-256-GCM with keys derived through PBKDF2-HMAC-SHA256. The manual iCloud setup copy uses AES-256-GCM with a separate random key stored in the synchronizable iCloud Keychain. These implementations use Apple's cryptography frameworks, not third-party cryptography.

16.Children

Persto is not directed to children under 13, or under the minimum age of digital consent in your region. We do not knowingly collect personal information from children.

17.Changes and contact

We may update this policy. Material changes will be reflected by a new effective date. Questions or data requests: support@perstofitness.com, which is read and answered by the person who wrote the app and is the fastest way to reach us.

Persto is operated by Constantia Technologies LLC, a Georgia limited liability company, which is the data controller for the limited information described in this policy.

Constantia Technologies LLC
1870 The Exchange SE, Ste 220, PMB 533704
Atlanta, GA 30339-2171
United States
+1 678 698 0469