Privacy Policy

Hiko does not collect, transmit, or store any of your data on external servers. Everything happens on your device.

Last updated: February 27, 2026

What Data Hiko Reads

With your explicit permission, Hiko reads the following from Apple HealthKit:

• Body measurements — body mass, height, lean body mass, biological sex
• Heart rate — real-time during workouts for sensor fusion
• Heart rate variability (HRV) — for readiness scoring
• Sleep analysis — for readiness scoring

Hiko uses this data solely to calculate accurate calorie expenditure using the LCDA metabolic equation.

What Data Hiko Writes

With your permission, Hiko writes the following to Apple HealthKit:

• Workout sessions — type, duration, route
• Active energy burned — LCDA-calculated calories
• Walking + running distance
• Route data — GPS coordinates for terrain detection

On-Device Processing

All computation happens locally on your iPhone and Apple Watch:

• LCDA metabolic calculations
• Terrain detection via OpenStreetMap tile data
• Interval walking timing
• Sensor fusion (heart rate, speed, altitude, terrain correlation)
• Readiness scoring

No data leaves your device. There are no servers to send it to.

What Hiko Does Not Do

• No user accounts or sign-in
• No cloud sync or remote storage
• No analytics or tracking
• No advertising or ad networks
• No data sharing with third parties
• No cookies or web tracking
• No fingerprinting

Data Storage

Workout history is stored locally using SwiftData on your device. This data never leaves your phone or watch.

Location Data

Hiko uses your location during workouts to detect terrain type via OpenStreetMap. Location data is processed on-device and used only for terrain coefficient calculation. Route data is stored in HealthKit if you grant permission.

How to Revoke Access

You can revoke Hiko's HealthKit permissions at any time:

1. Open the Settings app on your iPhone
2. Tap Privacy & Security
3. Tap Health
4. Tap Hiko
5. Toggle off any permissions you want to revoke

How to Delete Your Data

To delete all Hiko data, simply delete the app. All local data is removed with it. Workouts written to HealthKit remain in HealthKit and can be deleted through the Health app.

Contact

• Privacy questions: [email protected]
• General: [email protected]

Developer

Hiko is built by Larsen Studio, an independent app studio. We believe your health data is yours alone.