Question 1

How does the app measure stress?

Accepted Answer

The app uses Heart Rate Variability (HRV) readings captured continuously by your Apple Watch. HRV measures the variation in time (in milliseconds) between consecutive heartbeats. When you are calm, HRV is higher; when under mental or physical tension, HRV drops. Stress Tracker translates this into an intuitive 0–100 score.

Question 2

What data does the app collect, and where is it stored?

Accepted Answer

Stress Tracker collects zero personal data. All heart and sleep metrics are accessed directly from your Apple Watch via Apple HealthKit and remain strictly inside the local sandbox of your device.

Question 3

Which Apple Watch models are compatible?

Accepted Answer

Stress Tracker works on any Apple Watch running watchOS 10 or later, paired with an iPhone running iOS 17 or later.

Question 4

What is the Recovery Index, and how does it help me?

Accepted Answer

The Recovery Index evaluates how well your body restored itself overnight by comparing your sleeping HRV and resting pulse against your typical values. It tells you whether you are primed to push hard or should prioritize rest.

Question 5

Can I use the app without an Apple Watch?

Accepted Answer

No. An Apple Watch is required because heart rate variability is captured directly through the watch’s optical sensors into Apple Health.

Question 6

How do I use the daily and weekly evolution graphs?

Accepted Answer

The daily graph helps you see what happened throughout your day, pinpointing when stress spiked. The weekly view shows whether you are accumulating fatigue across consecutive days.

Question 7

Are there any subscriptions or hidden fees?

Accepted Answer

No. Stress Tracker is a single, one-time payment of 8.99€ on the App Store. There are no monthly fees, in-app purchases, or ads. All future updates are included.

Question 8

Can I show this data to my doctor?

Accepted Answer

Yes. While the app does not send data to the cloud, you can take screenshots of your daily timeline, recovery score, and weekly trends to share with a health professional.

Everything you need to know.