Comparison

Vigo vs Sthenos

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Vigo

Features
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Vigo is a light wellness app for tracking your daily state through body signals, subjective check-ins, and a calmer kind of self-observation. Instead of overwhelming you with raw numbers, Vigo turns signals like HRV, heart rate, respiratory rhythm, wrist temperature, gait, and environmental noise into a clearer picture of your current vigor. With Vigo, you can: See your current vigor at a glance Check which body signal is most active right now Follow your recent vigor tide across the week or month Add a quick subjective calibration when your body and your gut feeling are out of sync Get lightweight suggestions based on freshness, data quality, and your recent state Vigo is designed to feel soft, readable, and a little playful, while still helping you notice when it might be time to push, steady out, or recover first. Premium unlocks: Full weekly and monthly tide history Longer-term vigor trends Deeper state insights and interpretation Important: Vigo is a general wellness app. It is not a medical device and does not provide diagnosis or treatment advice. Terms of Use: https://xuzhifeng.github.io/Vigo-Support/terms/en/

About

Sthenos

Features
Read full description

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, steps, active energy, wrist temperature, body mass • For the optional fitness-age card: date of birth, biological sex, height, body composition, exercise and stand time, walking heart rate, mobility measures, daylight, blood glucose and pressure Nothing is written back to Apple Health. REQUIRES • iPhone with iOS 18 or later • Apple Watch (Series 4 or later) worn regularly, including overnight, for HRV and sleep. The watch app needs watchOS 11. • On-device AI insights require iOS 26 and an Apple-Intelligence-capable iPhone Sthenos is a personal wellness tool. It is not a medical device and does not provide medical advice. Apple Watch HRV is suitable for personal trends and is not clinical-grade. Always consult a healthcare professional for medical concerns.

Screenshots

Vigo4 screens
Sthenos4 screens

Verdict

The call

The clearest difference is price: Vigo at Free against Sthenos's $3.99. Sthenos's advantage is in-app purchases (none vs 1) and iOS requirement (18.0 vs 26.2). On ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Vigo is free to download; Sthenos costs $3.99 up front. Vigo sells 1 in-app purchase, starting at $2.99 per month. Sthenos asks for nothing beyond the download.

Scorecard3 real differences · 3 level
Vigo versus Sthenos: the parameters behind the verdict, then further details
ParameterVigoSthenos
PriceFree — better$3.99
Update frequency—Every 11 days
AdsNoNo
In-app purchasesYesNo — better
DevicesiPhoneiPhone, Apple Watch — better
Requires iOS26.218.0 — better
Further details — not scored
Size7 MB5 MB
Age rating4+4+
Developer志峰 许Georgios Stavropoulos

In-app purchases

1 purchases

Vigo

Subscriptions1
  • Vigo Pro Monthly7 Days trial$2.991 Month
None

Sthenos

No in-app purchases

Questions

Is Vigo free?
Vigo is free to download, with in-app purchases available.
Is Sthenos free?
Sthenos costs $3.99, with no in-app purchases.
Do Vigo or Sthenos have ads?
Neither Vigo nor Sthenos shows ads.

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