TensionRadar
HRV and stress at a glance
Free · In‑App Purchases
A little character that feels what your heart feels. HRV from Apple Watch, five watch complications, and character app icons. Nothing leaves your device.
TensionRadar turns the heart data your Apple Watch already records into a picture of your stress, with a small cartoon character that feels what your heart feels.
HOW IT WORKS
Heart rate variability (HRV) is the tiny variation between heartbeats. More variation means a relaxed, adaptable nervous system; less means load. TensionRadar learns your personal HRV baseline over a few weeks and scores every new reading against it, blended with how far your heart rate sits above resting. The result is a 0 to 100 stress score in five bands: Serene, Calm, Steady, Tense and Overloaded.
UPDATES AS DATA BECOMES AVAILABLE
TensionRadar reads new Apple Watch measurements from Health and supports background updates. Apple controls when HRV is measured and when apps and widgets refresh, so readings may be delayed and are not continuous. Open the app to check the latest available data.
BEAT-TO-BEAT DETAIL
The beat-to-beat recordings Apple Watch makes during Breathe and Mindfulness sessions are decoded on the phone, giving you RMSSD, SDNN and pNN50 alongside the daily SDNN trend.
COHERENCE BREATHING
Breathe at your resonance frequency with a paced circle. With the TensionRadar watch app, your Apple Watch measures your heart rate during the session and the coherence score updates in real time. Sessions are saved to Apple Health as Mindful Minutes.
TRENDS AND INSIGHTS
Daily HRV against your typical band, resting heart rate, HRV by hour of day, and a month-by-month mood calendar of character faces. Log coffee, sleep, workouts and how you feel; after a few entries TensionRadar shows which habits move your HRV.
MEET NIMBUS
Nimbus, a small cloud whose weather follows your heart, is free and breathes, blinks and droops with your data. The optional Character Pack adds Bloop the blob, Mochi the cat and Sprout the plant for $0.99, once, on all your devices.
WATCH COMPLICATIONS
Five complications for compatible watch faces and slots: your character with its stress ring, your HRV number against your typical range, a 0–100 stress score, heart rate with resting heart rate, and a seven-day HRV chart. The same set works on the iPhone Lock Screen.
PICK YOUR ICON
Choose the Nimbus radar icon or a character icon, or let the icon follow your character.
ALSO
• Home Screen widgets and an Apple Watch app that mirrors the radar on your wrist
• Rich watch notifications showing your character, stress band and HRV
• Tips that explain HRV, SDNN, RMSSD and every other number
• Morning summary and rate-limited tension alerts, only from real readings
• No account, no server, no analytics. Everything stays on your device.
REQUIREMENTS
iPhone with iOS 18 or later and an Apple Watch that records heart rate variability.
TensionRadar is a wellness tool, not a medical device. It does not diagnose or treat any condition.
Improves Character Pack purchasing with clearer loading, error messages, and retry. Clarifies monitoring status and fixes the radar ring at the maximum score.
The developer, Chen He, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Chen He
- Size
- 14.7 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Apple Watch
Requires watchOS 11.0 or later.
- iPhone
- Languages
English and 8 more
- English, French, German, Japanese, Korean, Portuguese, Simplified Chinese, Spanish, Traditional Chinese
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- In-App Purchases
Yes
- Character Pack $0.99
- Copyright
- © 2026 Chen He
