Comparison

Open Stress vs POTS Tracker

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

Head to head
About

Open Stress

Features
Read full description

Open Stress is a privacy-first iPhone wellness app for HRV observations already stored in Apple Health. It turns those sparse readings into on-device views of the latest raw SDNN value, a seven-day personal baseline, a personal HRV level, a separate personal stress estimate, and 7/30/90-day trend summaries. The app keeps individual HRV readings for today and the previous six local dates. Older readings are stored as daily averages. Personal estimates use retained raw readings; daily averages are not treated as individual samples. The app is designed around observations, not continuous monitoring. Today shows raw HRV in milliseconds, not a percentage. Trends reports counts and shares of observations rather than inventing stress duration. Insights explains freshness, context, and baseline coverage. General wellness information includes visible source links to Apple documentation and official WHO/CDC guidance. Sources & methods explains the references and the limits of the app-designed estimate. Open Stress reads Apple Health HRV. When iOS delivers a new qualifying observation, optional notifications can provide a local, timestamped update. The app has no account, product server, ads, or third-party analytics. Data are completely local on your iPhone. There is no account, sign-in, backend servers. As all apps should be. Start seven days of full app access without a subscription or automatic charge. After this local seven-day period, continued access requires an auto-renewable annual subscription or a restored purchase. The U.S. annual subscription price is $9.99 per year, and the App Store shows your localized price and applicable terms before purchase. Any Apple subscription introductory offer is separate from the local app-access period; Apple determines offer availability and eligibility. Unless canceled at least 24 hours before the current subscription or applicable introductory-offer period ends, the subscription renews automatically each year. You can manage or cancel it in App Store account settings. Restore Purchases is available in the app. Privacy Policy: https://kiskir.dev/projects/open-stress/privacy Terms of Use: https://kiskir.dev/projects/open-stress/terms Disclaimer: All data, analyses, and suggestions are for general reference only, not medical advice or clinically validated, personalized recommendations. HRV observations come from Apple Health. The personal estimate is an app-designed, unvalidated wellness heuristic. First-party Apple documentation and official WHO/CDC general guidance do not validate that estimate, explain an individual reading, or determine a suitable action for you. Do your own research and consult a qualified doctor or other appropriate professional when needed. Do not use this information as a basis for action or to replace or delay professional care.

About

POTS Tracker

Features
Read full description

Living with POTS or another form of dysautonomia? POTS Tracker helps you understand your symptoms, spot patterns, and finally show your doctor solid numbers instead of vague descriptions. Everything runs 100% locally on your iPhone – no account, no cloud, no sharing of your health data. WHY POTS TRACKER? With POTS (Postural Orthostatic Tachycardia Syndrome), the difference in your heart rate between lying down and standing up is often what matters most. That's exactly what you document here – day by day, ready for your next appointment or rehab. WHAT YOU CAN TRACK • Orthostatic reading: heart rate lying and standing, with the rise calculated automatically • Blood pressure, if you record it • Symptoms: palpitations, dizziness, lightheadedness, brain fog, fatigue, pre-syncope and more • Triggers & context: heat, fluids, salt, sleep, menstruation, stress • Free-text notes on every entry UNDERSTAND INSTEAD OF GUESSING • Clear trends over days and weeks • See what makes your symptoms better or worse • Keep good and bad days in view YOUR DOCTOR REPORT (main highlight) Generate a clean PDF report of your readings and symptoms with a single tap – ideal for cardiology, your GP, or rehab. Walk into your appointment prepared and save precious minutes. YOUR DATA STAYS YOURS • Stored 100% locally on your device • Backup export & import when you switch phones • No tracking, no ads, no account required A FAIR MODEL – NO SUBSCRIPTION Try it free for 14 days. After that, unlock all Pro features permanently with a single one-time payment. No subscription, no recurring fees. IMPORTANT NOTE POTS Tracker is a symptom diary for self-monitoring. It does not provide a diagnosis, is not a substitute for medical advice, and is not a medical device. For acute symptoms, please contact a healthcare professional.

Screenshots

Open Stress3 screens
POTS Tracker4 screens

Verdict

The call

The clearest difference is iOS requirement: POTS Tracker at 15.0 against Open Stress's 17.0. On price, update cadence, ads and in-app purchases there is nothing between them.

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

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

Both are free to download. Open Stress sells 1 in-app purchase, starting at $9.99 per year and POTS Tracker sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 23, 2026 and October 25, 2026 respectively.

Scorecard1 real difference Ā· 5 level
Open Stress versus POTS Tracker: the parameters behind the verdict, then further details
ParameterOpen StressPOTS Tracker
PriceFreeFree
Update frequencyEvery 3 weeksEvery 3 weeks
AdsNoNo
In-app purchasesYesYes
DevicesiPhoneiPhone, iPod — better
Requires iOS17.015.0 — better
Further details — not scored
Size6 MB50 MB
Age rating12+12+
DeveloperSihang ChenDaniel Gartler

In-app purchases

1 purchases

Open Stress

Subscriptions1
  • Open Stress Annual7 Days trial$9.991 Year
1 purchases

POTS Tracker

One-time1
  • POTS Tracker: Dysautonomia$17.99

Questions

Is Open Stress free?
Open Stress is free to download, with in-app purchases available.
Is POTS Tracker free?
POTS Tracker is free to download, with in-app purchases available.
Do Open Stress or POTS Tracker have ads?
Neither Open Stress nor POTS Tracker shows ads.
Which is updated more often, Open Stress or POTS Tracker?
Open Stress ships an update every 3 weeks, and POTS Tracker every 3 weeks. Most recently, Open Stress was updated on October 23, 2026 and POTS Tracker on October 25, 2026.

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