Privacy Policy

FLUX ("FLUX", "we", "us") builds an iOS running app that synchronizes your music to your live heart rate. This Privacy Policy explains what information we collect, how we use it, and the choices you have. By using FLUX you agree to this policy.

Information we collect

• Account information — when you sign up (with Apple, Google, email, or as a guest), we store an identifier and basic profile details such as your name or email, and your physiological profile (e.g., max and resting heart rate) used to calculate your training zones.
• Health & fitness data — with your permission, FLUX reads heart-rate and workout data from Apple Health (HealthKit) and connected devices (e.g., Apple Watch, Bluetooth chest straps, Garmin, Polar, COROS, WHOOP) during your runs to power real-time syncing and your Sync Score.
• Location data — with your permission, FLUX uses your device's precise location (GPS) during a run to map your route and calculate distance and pace. Your route stays on your device for private runs; it is uploaded to our servers only if you choose to share a run to the social feed. You can run without granting location.
• Motion & cadence data — with your permission, FLUX uses your device's motion sensors to measure your steps per minute (cadence), so it can match music tempo to your stride when no heart-rate sensor is connected. This is processed on your device.
• Workout & usage data — runs you record (duration, distance, pace, cadence, heart-rate zones, Sync Score), workouts you build, and in-app activity.
• Music metadata — track information from your connected Apple Music library (title, artist, ISRC) used to determine BPM and energy for syncing. We do not access your account password.
• Device & diagnostic data — basic device information and crash/diagnostic data to keep the app stable.

How we use your information

• To provide the core experience — matching music to your heart rate in real time and calculating your Sync Score.
• To sync workouts between coaches and athletes where you use Coach Mode.
• To improve reliability, fix bugs, and understand aggregate usage.
• To send you product updates if you opt in.

No advertising, no tracking

FLUX does not show ads, does not use your data for advertising, and does not track you across other companies' apps or websites. We do not sell your data.

Apple Health data

Health data accessed through HealthKit is used solely to provide app features to you. We do not use Apple Health data for advertising or marketing, and we do not sell it or share it with third parties for their own purposes.

Third-party services

FLUX relies on the following providers, each with their own privacy practices:

• Firebase (Google) — authentication, database, and storage for your account and workout data.
• Apple Music — to read your music library for syncing.
• Sentry — crash and error reporting, so we can find and fix problems in the app. It receives diagnostic data such as error details and basic device information — not your health data.
• Mixpanel — anonymous in-app usage analytics, so we can understand which features are used and improve the app. It receives an anonymous identifier and in-app events (such as features used and training-zone changes) — not your name, email, raw heart-rate readings, or location. You can opt out in the app settings.
• Cloudflare Web Analytics — privacy-friendly, cookieless website analytics (no personal profiles, no cross-site tracking).
• MailerLite — to send product-update emails if you opt in.
• BPM metadata service — our own server analyzes song tempo/energy by track identifier; it does not receive your personal or health data.

Data storage & security

Your data is stored on secured cloud infrastructure (Firebase), which may process it on servers outside your country. We take reasonable technical and organizational measures to protect it. No method of transmission or storage is 100% secure, but we work to safeguard your information.

Data retention

We keep your data for as long as your account is active. When you delete your account, your associated personal and workout data is deleted. Anonymized or aggregated data that no longer identifies you may be retained.

Your rights & account deletion

You can access and update your profile in the app. You may delete your account and associated data at any time from within the app (Settings → Delete account). You may also contact us to request access to or deletion of your data.

Children

FLUX is not directed to children under 13 (or the minimum age in your region), and we do not knowingly collect their data.

Changes to this policy

We may update this policy from time to time. Material changes will be reflected by the "Last updated" date above.

Contact

Questions about privacy? Email us at syncyourbeat@gmail.com.