Renfort.
Privacy Policy
Last updated: October 5, 2026
Renfort works without an account. Your settings and history stay on your device. Only the features listed below talk to our server, and advertising measurement happens only if you agree to it.
On your device only
- your settings (durations, tempo, voice, beeps);
- your session history (date, program, duration);
- the discomfort rating you choose to enter after a session;
- your level, streaks, achievements and challenge personal bests;
- the first name you enter for Duo sessions and duels, and your referral code.
This information stays on your device and is deleted if you uninstall the app (the only exceptions are what you choose to share for a Duo session, a duel or a challenge, and your time for the challenge of the week, see below). No health data is ever sent, neither to us nor to any third party.
Advertising measurement (only with your consent)
If you agree, the app tells Meta (Instagram, Facebook) that the app was installed, opened and that a session was completed, so we know which ads work. Meta also receives the technical information needed for this (IP address, device model, OS version). No advertising identifier, no health data and none of your session content is sent. This measurement is only for people aged 15 and over. Without your consent, nothing is sent. You can withdraw your consent at any time in Settings → Ad measurement (Meta). This data is processed by Meta Platforms Ireland Ltd under its privacy policy.
Duo sessions and live duels (only if you use them)
When you create or join a Duo session or a live duel, the app connects to our server so that the session or the duel starts and runs at the same time for you and the other person. The server only receives: the first name you enter, your referral code, the chosen program or position, your progress or your hold time, and the predefined reactions and quick messages you send. This is passed on to the other person and kept in memory for the duration of the session or duel, then erased. For a scheduled duel, the chosen time, the position and your first name are kept until 6 hours after the planned time. No health data (discomfort, history) is sent. There is no free-text chat: only predefined messages can be exchanged.
Camera during a duel (optional, off by default). If you turn on your camera during a duel, your video (without sound) goes directly from your device to your opponent's, encrypted. When a direct connection is not possible, it is relayed by Cloudflare's servers, still encrypted. The video is never recorded or stored, by us or anyone else, and stops as soon as you turn the camera off or the duel ends.
The server is hosted by Heroku (Salesforce) in the European Union. Like any web server, it sees your device's IP address during the connection. Invitation links contain a temporary code and the first name of the person inviting.
Challenges between friends
A challenge link contains your first name, your score and your referral code. It is read by the person you send it to, and by our server to display the challenge page; nothing is stored.
Anonymous statistics
To learn what is useful in the app, it sends usage events to our server: app opened, session started or completed, check-in done (without the discomfort rating), challenge tried or shared, interest in Renfort+, Duo session, duel. They are linked to an identifier drawn at random on the device (renewed every 13 months), never to your identity, your Apple Account or an advertising identifier. Our server only keeps daily counters and, for each identifier, the day of the first launch and the days of use during the first month. No health data (pain, discomfort, Apple Health) is sent. You can turn these statistics off at any time in Settings ("Anonymous statistics").
#BeatMira, the challenge of the week
Every week, Mira (virtual coach, AI) sets a time on a challenge. When you take part, the app sends our server your time and a random code specific to the device (so only your best time counts), to compute the participants' median. Your first name is only sent if you check "Show my first name in the weekly top 3"; you can uncheck it at any time. These scores are kept for 16 weeks at most. No health data is sent.
The score card you can share (Story format) is created on your device; you decide whether to post it.
Apple Health (only if you turn it on)
On iPhone and iPad, you can turn on Apple Health in Renfort's Settings. The app then saves your sessions as workouts and your breathing or relaxation exercises as Mindful Minutes. It also reads today's step count and last night's sleep duration, only to tailor Mira's advice on screen. This data stays on your device: it is never sent to our servers, to Meta or to any other third party, and is never used for advertising. You can remove access at any time in the iPhone Settings (Health → Data Access & Devices → Renfort).
Reminders and breaks
Daily reminders and active-break reminders are notifications scheduled on your device. No server is involved.
Virtual coach
Mira, Renfort's coach, is a character created with artificial intelligence (images, videos and voice). She does not collect anything about you.
AirPlay and Apple TV
Showing a session on an external screen (AirPlay, HDMI) sends no data to our servers. The Apple TV app sends the same anonymous statistics as the iPhone app (see above), which you can turn off in its Settings; it does not use Apple Health, notifications or the camera.
Children and minors
Renfort is not intended for children and collects no data about them. The optional sharing of advertising measurement data with Meta is limited to people aged 15 and over; below that age, decline the prompt or turn it off in Settings.
Your rights
Under the GDPR, you can request access to or deletion of your data by writing to us. The data on your device is erased when you uninstall the app; for advertising measurement, simply withdraw your consent in Settings. Data controller: VOID.