Privacy policy

Last updated: November 2, 2026

In short. Stamio does all its calculations on your iPhone and Apple Watch. Your health data never leaves your devices unless you ask: no account, no ads, no analytics. Nothing is sold or shared. The one exception, at your request and with your consent: a workout you upload to your own Strava account, straight from your iPhone (see "Connecting to Strava"). If you turn it on, a copy of your plan, your entered race times and your preferences is kept in your own iCloud, never your health data (see "Copy in iCloud"). If you connect your Strava account to import your routes, the sign-in goes through a small Stamio server that keeps nothing (see "Connecting to Strava"). If you download a map area or create a route, your iPhone reads that area's map (and elevation) pieces from Stamio's map server and sends nothing else (see "Maps" and "Creating a route"). The only other exception, during the beta: an export you choose to send yourself (see "Beta version").

Who makes Stamio

Stamio is made by Charles Lapointe, an independent developer based in France. For any question about your data: [email protected].

What Stamio reads from Health

With your permission, Stamio reads from Apple's Health app:

• your workouts: type, duration, distance, GPS route, heart rate, running power and stride, effort rating;
• your heart: heart rate, resting heart rate, heart rate variability (HRV) and beat-to-beat intervals;
• your nights: sleep and sleep stages, respiratory rate, wrist temperature, blood oxygen;
• your day: steps, active and resting calories, and the VO2 max estimated by Apple (only to compare);
• your profile: age, sex, weight, height, BMI, wheelchair setting.

Each piece of data feeds a calculation: VO2 max, training load and status, readiness, energy, sleep score, race predictions, training plan. You choose what you share in the Health sheet, and you can remove access at any time in Settings › Apps › Health › Data Access & Devices › Stamio. Values that depend on it then no longer appear.

If you pair a chest strap (advanced setting), Stamio reads its heart rate over Bluetooth during your runs, on your iPhone only.

When you record a run with Stamio on your watch (Activities, on the watch), Stamio uses your location during the run, with your permission, to measure distance and draw your route. Your location is only used during the run and is never sent anywhere: the route is saved to Health with the run.

What Stamio writes to Health

What you enter yourself: your naps, weight, height and how hard a workout felt. And the runs you record with Stamio on your watch, just like the Workout app does: the workout, its route, and what the watch measured during the run (heart rate, distance, calories, power and running form). Stamio never writes its own estimates (VO2 max, readiness, energy…) to Health. A note you leave on the watch after a run goes to that workout's notes on your iPhone, never to Health.

Where your data lives

• Calculation results (your VO2 max history, training loads, training plan, settings) are stored in the app, on your iPhone. They are sent to your Apple Watch through Apple's iPhone–watch connection, so the watch shows the same values.
• Stamio has no server that keeps your data. It sends nothing over the internet, except the copy in your iCloud if you turn it on, the Strava connection and the workouts you upload there, if you ask for them and the map downloads you choose (see below). The app contains no third-party analytics, advertising, tracking or crash reporting tools.
• Like any app, these files are part of your iPhone backup (iCloud or computer) if you turned it on. That backup is managed by Apple.
• Nothing leaves Stamio unless you ask: plan workouts sent to the Workout app on your watch, and the plan PDF if you choose to share it.

Copy in iCloud

If you turn it on (on the plan screen or in Settings › Data and health › "Copy in iCloud"), Stamio keeps a copy in your iCloud so you get your plan back after a reinstall or on a new iPhone:

• What is copied: your training plan (and the next plan you scheduled), the race times you entered by hand and your preferences (unit, step goal, home cards, appearance, watch and run recording settings).
• What is never copied: your health data and everything Stamio calculates from it (recalculated from Health on the new iPhone), your workout notes, your age, sex, weight, height, the heart rates you entered, the medication that affects your heart rate, the wheelchair setting, the reason for a comeback and your answers to "How did it feel?".
• Where: in the iCloud storage of your Apple Account, reserved for Stamio and managed by Apple. The developer has no access to it and receives nothing.
• How long: as long as the copy is on. Turning it off, or "Delete app data", erases the copy from iCloud.

If two iPhones use the same copy, Stamio asks you which plan to keep before replacing one with the other.

Connecting to Strava

Optional: only if you choose the Routes tab › Add › "From Strava" (routes), or "Upload to Strava" (workouts: workout details › Share, or Settings › Strava).

• What Stamio reads from Strava: the list of your routes (name, distance, elevation) and the track of the ones you import. Never your Strava activities or your health data.
• What Stamio sends to Strava, only if you ask: the workout you upload (the "Upload to Strava" button) or, if you turn on "Upload my workouts to Strava", every activity recorded with Stamio after you turn it on. The file contains the activity type, time, duration, distance, calories, GPS track and heart rate, with a name (for example "Intervals · Stamio") and a short line "Recorded with Stamio · stamio.app". It goes straight from your iPhone to your Strava account: no Stamio server sees it. Before the first upload, the app tells you what is sent and asks for your consent. On Strava, the workout follows your Strava settings (visibility, privacy zones); you can edit or delete it on Strava. Stamio keeps on your iPhone the list of uploaded workouts, so it never uploads one twice.
• How: you authorize Stamio on Strava's page. The authorization code Strava sends back is exchanged for access by a small Stamio server (hosted by Cloudflare), because the secret key of the Strava application can't be inside the app. This server passes the request to Strava and returns the answer to your iPhone; it records nothing (not the access, not your Strava ID, not your IP address in any Stamio log).
• Where: access to your Strava account is kept in your iPhone's keychain, on this device only (never in iCloud). Imported routes become routes that stay on your iPhone and your watch.
• How long: until you disconnect ("From Strava" › "…" › "Disconnect from Strava") or remove Stamio from the authorized apps in Strava's settings. "Delete app data" also erases the access. Automatic upload stops as soon as you turn it off or disconnect; workouts already uploaded stay on Strava, where you can delete them.
• What Strava does with your data is covered by Strava's privacy policy.

Maps

Optional: only if you download an area (Routes tab › Maps on your watch, or "Download the map around it" on a route).

• What is requested: your iPhone reads, from Stamio's map server (a file hosted by Cloudflare), the map pieces that cover the chosen area. As with any web page, the server receives your iPhone's IP address and the pieces requested, so roughly where the area is; no account, no identifier, no measured location, no health data. Stamio keeps no log of these requests.
• Where: the drawn map stays on your iPhone and your watch (sent over the link between them) and works with no signal.
• How long: until you remove the area; "Delete app data" also erases all maps.
• Map data © OpenStreetMap contributors (ODbL license), tiles by Protomaps.

Creating a route

Optional: only if you create a route (on iPhone: Routes tab › Add a route › Create a route; on the watch: a run's start screen › route › Create a route).

• What is requested: as with maps, your iPhone reads the map and elevation pieces around the chosen start from Stamio's map server; the server receives your iPhone's IP address and the pieces requested, nothing else. The route is calculated on your iPhone.
• From the watch: the start is your watch's location, the one its GPS is already reading on the start screen. If your iPhone is nearby, the watch sends it that location over the link between them, and your iPhone reads the map and does the math; otherwise, your watch reads the map and elevation pieces around it itself (Wi-Fi or cellular) and does the math. Either way, the server only receives the device's IP address and the pieces requested; your location is never kept or sent anywhere else. The route you follow is saved on your watch and your iPhone.
• Usual start: Stamio reads from Health the starting point and elevation gain of your latest outdoor runs, to suggest your usual start and your usual terrain. These values stay on your iPhone and aren't kept.
• Searching for a place: the text you type is sent to Apple Maps search (as in the Maps app), along with the map area.
• My location: if you pick "My location" as your start, Stamio asks for permission to read your iPhone's location ("While Using the App"). It's read once, on your iPhone, to place the start, and it's never kept or sent anywhere. Once allowed, it's also used as the start when you open "Create a route" far from your usual start. You can turn it off in Settings › Stamio › Location.
• Reported spots: the places you report to avoid stay on your iPhone; "Delete app data" erases them.
• Elevation © Mapterhorn, from Copernicus and IGN.

Stamio Pro and purchases

Stamio Pro purchases (subscription or lifetime) go through the App Store and are handled by Apple: the developer never receives your name, email address or payment details. Stamio only checks, on your iPhone, whether Stamio Pro is active, and tells your watch. You manage or cancel your subscription in your Apple Account settings (or Settings › Stamio Pro › “Manage my subscription”). Stamio Pro doesn't change any calculation: it unlocks the display of some features.

How long

As long as the app is installed. Settings › Data and health › "Delete app data" erases everything Stamio stored (calculations, plan, settings, routes, maps, iCloud copy, Strava access) without touching Health. Deleting the app erases what is on the iPhone (Strava access is removed on reinstall); the iCloud copy stays for a reinstall (turn it off first to erase it too). What you wrote to Health stays in Health, where you can delete it.

Your rights

Apart from the beta sign-up on the website (see below), none of your data ever reaches us, so we hold nothing about you and there is nothing to access, correct or erase on our side. Everything is managed in the app and in Health. For any question, write to us ([email protected]). You can also file a complaint with the French data protection authority, the CNIL (cnil.fr).

Beta version

Test versions distributed through TestFlight (never the App Store version) offer "Share my data for the beta" in Settings › Advanced. Nothing is sent without your explicit consent, given in the app, and you send the file yourself (by email or with the iOS share sheet).

• What is sent: the values Stamio calculated over the last 150 days (VO2 max, load and effect of each workout, readiness, score and stages of each night, energy, daily stress, training status, resting heart rate of each night) and your profile (age, sex, weight, height, max and resting heart rate used, heart-rate medication, wheelchair), under a tester number.
• What is never sent: your raw measurements (second-by-second heart rate, heartbeats, GPS routes), your name, your Apple ID, your workout notes. Your email address is only known if you send the file by email.
• Why: only to check and improve Stamio's calculations, by comparing them with how you feel or with another watch. Legal basis: your explicit consent (health data).
• Where and for how long: on the developer's computer, never shared or sold; deleted no later than 3 months after Stamio's release on the App Store.
• Your rights: you can withdraw your consent at any time (uncheck it in the app, and write to [email protected] to have your files deleted), and ask for a copy or deletion of what was sent.

TestFlight itself is an Apple service: it may give the developer your invitation email address, your feedback and crash reports, under Apple's privacy policy.

If you live in the United States (in particular Washington, Nevada or Connecticut), our Consumer Health Data Privacy Policy adds to this section: stamio.app/health-data-privacy.html, also in the app under Settings › About.

Beta sign-up on stamio.app

The form on the stamio.app home page, separate from the app, is only used to send you beta news and your 3-month Stamio Pro code at launch.

• What is stored: your email address, your watch model if you give it, the page language, the sign-up date and position and your consent. Not your name, not your IP address, no health data.
• Why: to write to you about the beta, with your consent (checkbox). Never ads, never sold or shared.
• Where: in a Cloudflare database (the site's host), whose servers may be outside the European Union (transfers covered by the European Commission's standard contractual clauses).
• How long: until your code is sent, and at the latest 12 months after Stamio's App Store release.
• Your rights: reply "stop" to any email or write to [email protected], and your address is erased. You can also ask to see or correct it, or file a complaint with the CNIL (cnil.fr).

Visit statistics on stamio.app

The website (not the app) counts its visits with Cloudflare Web Analytics, our web host's tool: page views, most-read pages, country and device type, as aggregate numbers only. No cookies, no identifiers, no cross-site tracking and no visitor profiles: these numbers can't be used to recognize you. They only tell us which pages get read, so we can improve the site.

If this changes

If a future version ever needed data to leave your devices (for example an online backup or a test program), this policy would be updated first, and the app would clearly ask for your consent. Without it, nothing would be sent.

Not a medical device

Stamio is not a medical device. It does not diagnose, treat or prevent any disease. Its values are estimates to help you train. If you have any doubt about your health, talk to a doctor.