TensionRadar
iPhone · Apple Watch
A little character that feels what your heart feels.
TensionRadar turns the heart data your Apple Watch already records into a picture of your stress. Available heart rate variability readings from Health are scored against your own baseline and shown as one of five moods on a cartoon character — on your phone, in a widget, on your wrist and on your watch face.
Requires iOS 18 or later and an Apple Watch with watchOS 11 or later.
What it does
A radar, not a number
Every HRV reading is scored against your personal baseline and blended with how far your heart rate sits above resting. The result is a 0–100 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 HRV measurement and app and widget refresh timing, so readings may be delayed and are not continuous. Open the app to check the latest available data.
Four characters, five moods
Nimbus the cloud breathes, blinks, and rests with your data. The optional Character Pack adds Bloop the blob, Mochi the cat, and Sprout the plant, each with five expressive moods and a matching app icon.
Coherence breathing
Breathe at your resonance frequency with a paced circle. With the watch app measuring, your coherence score updates in real time, and finished sessions are saved to Health as Mindful Minutes.
Trends and a journal that learns
Daily HRV against your typical band, resting heart rate, HRV by hour of day and a mood calendar of character faces. Tag coffee, sleep or workouts and see which habits move your HRV.
Five watch complications
Your character, your HRV number, a 0–100 stress score, heart rate with resting, and a seven-day HRV chart — with layouts for compatible watch faces and complication slots, plus widgets for the iPhone Lock Screen. Available layouts vary by metric.
Pick your app icon
Keep the Nimbus radar icon or switch to a character icon in Settings, or let the Home Screen icon follow whichever character you pick.
Alerts on your wrist
When an eligible reading triggers an alert and the system delivers it to your watch, the notification shows your character, the stress band and your HRV. Every number in the app has a tip explaining what it means.
Privacy first
TensionRadar reads heart data from Apple Health on your device and keeps everything it derives there. No account, no server, no analytics, no third-party SDKs. The only thing it writes back to Health is the breathing sessions you finish. The full story is on the privacy page.
Not a medical device
HRV reflects sleep, training, illness, caffeine, alcohol and stress all at once. TensionRadar is a wellness tool for noticing patterns, not for diagnosing or treating anything.