Comparison

Quell Flex vs Migraine Sentry

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

Head to head
About

Quell Flex

Features
Read full description

After pairing their Quell Flex devices to the Quell Flex app, users can: - Start and stop therapy - Control stimulation intensity - Check therapy status (e.g., time left in session) - Check device battery level - Review informational videos and other materials related to the devices * You should consult your physician before making changes to your chronic pain treatment plan.

About

Migraine Sentry

This app forecasts migraine vulnerability by analyzing your personal health data, weather, and environmental factors. It provides daily and weekly outlooks, identifies personal triggers, and offers insights into effective treatments. Log migraines quickly and receive a clinical report for your doctor.

Highlights
  • Personalized migraine vulnerability forecast
  • Seven-day outlook based on weather and patterns
  • Passive health data analysis (sleep, HRV, heart rate)
  • Personal trigger rankings
  • Plain-language explanation of deviations
  • Fast logging with Live Activity
  • Clinical PDF report for doctors
Features
Read full description

Know before the pain, without logging everything. Most migraine trackers ask you to record everything. Migraine Sentry works differently. It uses Apple Watch, Apple Health and weather data to build a picture of your personal baseline. Your devices collect the signals. You log the migraine. Migraine Sentry connects the two. Once your baseline is ready, each morning brings a simple Low, Moderate or Elevated vulnerability forecast. Look seven days ahead for pressure-related and cycle-related risk. As your history grows, Migraine Sentry explains what changed before your attacks, ranks the signals most closely linked to them and shows which treatments appear to work best for you. WHAT YOU GET • A personal migraine vulnerability forecast each morning • A seven-day outlook based on weather, pressure and your own patterns • Passive analysis of sleep, HRV, resting heart rate, activity, wrist temperature and more, where available • Personal trigger rankings based on attacks and normal days • Plain-language explanations of what differed from your baseline • Fast logging from iPhone or Apple Watch, with an active migraine shown through a Live Activity on your Lock Screen • Optional check-ins for stress, hydration, caffeine, alcohol and skipped meals • Cycle awareness for cycle-related patterns, if you choose • A clear clinical PDF for your doctor or neurologist HOW IT LEARNS Log a migraine and Migraine Sentry captures the surrounding context. After several attacks, it begins surfacing emerging patterns. With more history, it becomes better able to distinguish signals that appear before your migraines from signals that are also common on normal days. NO APPLE WATCH? You can still use migraine logging, iPhone pressure readings, weather, check-ins, history and reports. Compatible wearables that write sleep and heart-rate data to Apple Health can provide additional signals. PRIVATE BY DESIGN Raw Apple Health readings are processed on your iPhone and never sent to our servers. Migraine entries and settings can back up through your private iCloud account. Migraine Sentry does not operate a migraine-data server. FREE AND PREMIUM Migraine logging, history, check-ins, your daily forecast level and the core clinical report are free. Migraine Sentry Premium adds the reasons behind your forecast, live signal nudges, detailed seven-day outlook information, personal trigger rankings, pattern and treatment insights, and expanded report analysis. Every new user receives a 21-day full-access Premium Preview once their forecast is ready. The preview does not start a subscription or renew automatically. Premium is an auto-renewing subscription with a 21-day full-access preview for every new user. Payment is charged to your Apple Account at purchase confirmation. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. Manage or cancel anytime in Settings. Migraine Sentry is not a medical device. It does not diagnose, treat, or prevent any condition. Forecasts and insights are informational only. Always consult your healthcare provider about your migraines. Privacy Policy: https://migrainesentry.com/privacy Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Quell Flex4 screens
Migraine Sentry4 screens

Verdict

The call

The clearest difference is in-app purchases: Quell Flex at none against Migraine Sentry's 2. Migraine Sentry's advantage is update cadence (every 3 days vs every 35 months). On price, ads, device support and iOS requirement 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

Both are free to download. Migraine Sentry sells 2 in-app purchases, starting at $4.99 per month. Quell Flex asks for nothing beyond the download.

UpkeepUpdate frequency

Quell Flex ships an update every 35 months, Migraine Sentry every 3 days. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

Scorecard2 real differences · 7 level
Quell Flex versus Migraine Sentry: the parameters behind the verdict, then further details
ParameterQuell FlexMigraine Sentry
PriceFreeFree
Rating—4.5 (2 ratings) — better
Number of ratings—2 — better
Update frequencyEvery 35 monthsEvery 3 days — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Freemium
DevicesiPhoneiPhone, Apple Watch — better
Requires iOS16.6 — better17.0
Further details — not scored
Size23 MB16 MB
Age rating12+12+
DeveloperNeuroMetrix, Inc.KJC International Limited

In-app purchases

None

Quell Flex

No in-app purchases

2 purchases

Migraine Sentry

Subscriptions2
  • Premium Monthly$4.991 Month
  • Premium Annual$29.991 Year

Questions

Is Quell Flex free?
Quell Flex is free to download, with no in-app purchases.
Is Migraine Sentry free?
Migraine Sentry is free to download, with in-app purchases available.
Do Quell Flex or Migraine Sentry have ads?
Neither Quell Flex nor Migraine Sentry shows ads.
Which is updated more often, Quell Flex or Migraine Sentry?
Quell Flex ships an update every 35 months, and Migraine Sentry every 3 days. Most recently, Quell Flex was updated on October 25, 2026 and Migraine Sentry on October 24, 2026.

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