Sthenos
Not in any tracked top chart right now.
Updated 23 Oct 2026 · rankings refresh through the day
DeveloperGeorgios Stavropoulos
CategoryHealth & Fitness
Price3.99 EUR
Released
Rating★ 0.0 (0)
Version2.7
Age rating4+
First seen by us
12 Oct 2026
12 Oct 2026Rating
0.0 ★
0 ratings
Measured
Sthenos on the App Store
App details
App ID
6760965966
Publisher
Georgios Stavropoulos
On the store since
Mar 2026
Under a year
Minimum OS
iOS 18.0+
iPhone XS and later
Devices
iPhone · iPad · Watch
Content rating
4+
Languages
8
EN FR DE EL IT JA PT ES
Size
5 MB
Where it ranks now
Every top chart it appears in across 30 countries.
| Country | Charts | Rank |
|---|---|---|
| Not charting right now. | ||
Ratings
App Store, worldwide.
Rating
0.0 ★
0 ratings
Measured
Ratings
0
Measured
About Sthenos
Do you know how much energy you actually have left right now?
Sthenos turns your Apple Watch into a live energy score — a single number from 0 to 100 that reflects how recharged or depleted your body is, and whether you're charging or draining at this moment.
No guesswork. No manual logging. Just honest, science-backed insight from the sensors you already wear.
HOW IT WORKS
Sthenos isn't a daily snapshot or a one-off rating. It's a running energy level, updated through the day:
• You recharge during genuine rest and sleep — when your heart rate settles and your HRV rises relative to your own baseline.
• You drain from activity, elevated heart rate, and physiological stress.
• Recent training still counts — a hard workout keeps weighing on you for days, so you can tell when you're truly recovered.
Everything is judged against YOUR personal baseline, not population averages. Sthenos learns your normal (about two weeks — faster if you've already been wearing your watch) and calibrates the score to your body.
WHAT YOU GET
• The heart gauge — your score fills a heart that empties as you deplete and refills as you recover. The number sits inside it and inverts where the waterline crosses, and it beats at your own resting heart rate.
• Energy flow — a live read on whether you're charging or draining this hour, and why.
• Sleep, Recovery, Heart and Freshness — the four things moving your score, each one tappable for a plain-English explanation of what it means today.
• Trends — your history drawn as a tide, at a day, a month, three months or six, from the same model as the live score.
• Training load — Fitness, Fatigue and Form from the training impulse of every workout, with the raw daily load drawn underneath, plus the acute:chronic ratio and its sweet spot.
• Vitals — every reading your watch takes, each on a rail showing your own normal range and where today sits: heart rate, resting HR, HRV, blood oxygen, respiratory rate, VO₂ max, steps, active energy, sleep, wrist temperature, weight.
• On-device AI insights — a short, plain-language read on your day, generated on your iPhone with Apple Intelligence.
• Apple Watch app and complications — your score, factors, vitals and training load on the wrist, plus the score as a filling heart, a training-load complication, and a configurable single metric.
• Home-screen widgets — a score widget, plus two configurable Vitals widgets where you choose every metric shown.
• The science, in-app — an About tab explaining how the score is calculated, with links to the research, and saying plainly where the evidence is contested.
PRIVATE BY DESIGN
Your health data never leaves your device. Sthenos reads from Apple Health and computes everything locally — no account, no sign-up, no tracking, no ads, no servers. Even the AI insights run on-device.
WHAT IT READS (read-only, from Apple Health)
• For the score: HRV, resting heart rate, heart rate, sleep, workouts
• For Vitals: blood oxygen, respiratory rate, VO₂ max
Sthenos turns your Apple Watch into a live energy score — a single number from 0 to 100 that reflects how recharged or depleted your body is, and whether you're charging or draining at this moment.
No guesswork. No manual logging. Just honest, science-backed insight from the sensors you already wear.
HOW IT WORKS
Sthenos isn't a daily snapshot or a one-off rating. It's a running energy level, updated through the day:
• You recharge during genuine rest and sleep — when your heart rate settles and your HRV rises relative to your own baseline.
• You drain from activity, elevated heart rate, and physiological stress.
• Recent training still counts — a hard workout keeps weighing on you for days, so you can tell when you're truly recovered.
Everything is judged against YOUR personal baseline, not population averages. Sthenos learns your normal (about two weeks — faster if you've already been wearing your watch) and calibrates the score to your body.
WHAT YOU GET
• The heart gauge — your score fills a heart that empties as you deplete and refills as you recover. The number sits inside it and inverts where the waterline crosses, and it beats at your own resting heart rate.
• Energy flow — a live read on whether you're charging or draining this hour, and why.
• Sleep, Recovery, Heart and Freshness — the four things moving your score, each one tappable for a plain-English explanation of what it means today.
• Trends — your history drawn as a tide, at a day, a month, three months or six, from the same model as the live score.
• Training load — Fitness, Fatigue and Form from the training impulse of every workout, with the raw daily load drawn underneath, plus the acute:chronic ratio and its sweet spot.
• Vitals — every reading your watch takes, each on a rail showing your own normal range and where today sits: heart rate, resting HR, HRV, blood oxygen, respiratory rate, VO₂ max, steps, active energy, sleep, wrist temperature, weight.
• On-device AI insights — a short, plain-language read on your day, generated on your iPhone with Apple Intelligence.
• Apple Watch app and complications — your score, factors, vitals and training load on the wrist, plus the score as a filling heart, a training-load complication, and a configurable single metric.
• Home-screen widgets — a score widget, plus two configurable Vitals widgets where you choose every metric shown.
• The science, in-app — an About tab explaining how the score is calculated, with links to the research, and saying plainly where the evidence is contested.
PRIVATE BY DESIGN
Your health data never leaves your device. Sthenos reads from Apple Health and computes everything locally — no account, no sign-up, no tracking, no ads, no servers. Even the AI insights run on-device.
WHAT IT READS (read-only, from Apple Health)
• For the score: HRV, resting heart rate, heart rate, sleep, workouts
• For Vitals: blood oxygen, respiratory rate, VO₂ max
Latest updates
2.7
SPEAKS EIGHT LANGUAGES
Sthenos is now in English, Spanish, French, German, Japanese, Italian, Brazilian Portuguese and Greek — the app, the home-screen widgets, the watch app and the complications, down to the Health permission prompts you read on first launch.
The Today insight answers in your language too, but only when the on-device model genuinely speaks it. Asked for a language it was not trained on, the model produces a confident imitation rather than declining, which serves you worse than plain English — so in that case the card stays in English.
VOICEOVER AND LARGER TEXT
• Every chart describes itself now: where the reading sits, the range it covered, how many readings it holds and which way it is going. Direction is judged across the whole series, so one spike at either end cannot name a trend.
• All four tabs are reachable end to end, and the tab you are on is spoken.
• Text follows your text-size setting properly. Numerals that stayed small however large you set it now scale, and dense rows reflow rather than truncate.
• Icon-only controls and decoration are labelled or hidden, so a row reads as one sentence instead of four loose fragments.
FIXED
• A score of zero now reaches the widget and the watch. They could keep showing the previous number while the app itself correctly showed zero — a genuinely depleted day was being mistaken for missing data.
Everything is still computed on your device. No account, no servers, no tracking.
