Comparison

Peak Flow Log vs Peak Flow Diary | Asthma

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

Head to head
About

Peak Flow Log

This app helps you monitor your asthma and peak flow readings. It uses a color-coded system to indicate the quality of your measurements. Additional features are available through a premium version.

Highlights
  • Track asthma and peak flow
  • Color-coded value indicators
  • Premium features available
  • Feature requests welcome
Features
Read full description

Simple app to track your asthma / peak flow. A colour indicates how good your value is. More features are avaliable with Peak Flow Log Plus. More features are planned. Feature requests are welcome!

About

Peak Flow Diary | Asthma

Easily record daily peak flow values and visualize breathing changes with clear graphs. Understand your asthma trends, identify early warning signs, and support your health management. Useful for medical visits and daily care.

Highlights
  • Daily peak flow recording
  • Easy input methods (slider/keyboard)
  • Zone-based graph display
  • Record list with memo management
  • Cloud storage and account support
  • Intuitive and simple operation
Features
Read full description

Understand Your Breathing, Every Day. Peak Flow Diary is an easy-to-use app that helps you record your daily peak flow readings and track changes in your breathing over time. With just a few seconds of recording each day, you can better understand: • Your usual breathing condition • Changes and trends in your breathing • When your condition starts to worsen Color-coded zones make it easy to see your current breathing status at a glance, helping you manage your respiratory health every day. 【Key Features】 ■ Quick and easy daily recording Record your peak flow in seconds using either the slider or keyboard input. Choose the method that works best for you. ■ Color-coded graphs View your peak flow readings in easy-to-read graphs. Color-coded zones help you quickly understand your current condition and identify trends over time. ■ History and notes Review all your previous records in one place. You can also save notes about your symptoms, activities, or daily events. ■ Medical Report (PDF) Automatically generate a PDF medical report from your recorded data. Print it or show it on your smartphone to help explain your condition during medical appointments. ■ Reminder notifications Set reminders so you never forget to record your peak flow. ■ Secure cloud backup Your records are safely stored in the cloud, making it easy to restore your data when changing devices. ■ Simple and intuitive design Designed to be easy to use every day, so you can build a lasting habit. 【Premium】 Unlock additional features to gain deeper insights into your breathing. ■ Breathing Monitor Analyzes your daily peak flow readings and sends push notifications when sudden drops or declining trends are detected. ■ Long-term analysis View your peak flow data over an entire year to identify long-term trends that may not be visible within just 28 days. ■ Comparison graphs Compare your current data with the previous year to better understand seasonal changes and long-term patterns. ■ Extended Medical Reports Generate PDF medical reports covering up to one year of recorded data. ■ Ad-free experience Enjoy the app without advertisements. Keeping a daily record is the first step toward better understanding your breathing. Start tracking your breathing today with Peak Flow Diary. Peak Flow Diary Terms of Service https://susatthi-asthma-diary-prod.web.app/terms-of-service.html?lang=en Peak Flow Diary Premium Terms of Service https://susatthi-asthma-diary-prod.web.app/terms-of-service-premium.html?lang=en

Screenshots

Peak Flow Log3 screens
Peak Flow Diary | Asthma4 screens

Verdict

The call

The clearest difference is ads: Peak Flow Log at none against Peak Flow Diary | Asthma's shown. Peak Flow Log also leads on review sentiment (100% vs 74%) and rating (5.0 vs 4.7). Peak Flow Diary | Asthma's advantage is ratings volume (36 vs 1) and iOS requirement (15.0 vs 26.2). On price, update cadence, in-app purchases and monetization model 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. Peak Flow Log sells 1 one-off in-app purchase and Peak Flow Diary | Asthma sells 2 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Peak Flow Log holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Peak Flow Diary | Asthma has 36 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of Peak Flow Log's written reviews are positive against 74% of Peak Flow Diary | Asthma's.

UpkeepUpdate frequency

Peak Flow Log ships an update every 2 weeks, Peak Flow Diary | Asthma every 3 weeks. The most recent releases landed on October 10, 2026 and October 27, 2026 respectively.

Scorecard5 real differences · 5 level
Peak Flow Log versus Peak Flow Diary | Asthma: the parameters behind the verdict, then further details
ParameterPeak Flow LogPeak Flow Diary | Asthma
PriceFreeFree
Rating5.0 (1 ratings) — better4.7 (36 ratings)
Positive reviews100.0% of reviews — better74.2% of reviews
Number of ratings136 — better
Update frequencyEvery 2 weeks — betterEvery 3 weeks
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS26.215.0 — better
Further details — not scored
Size5 MB57 MB
Age rating4+4+
DeveloperFriedrich EwaldKeyber Inc.

Customer experience

Peak Flow Log

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Peak Flow Diary | Asthma

All ratings35 ratings
Positive97.1%
Neutral0.0%
Negative2.9%
Written reviews31 reviews
Positive74.2%
Neutral16.1%
Negative9.7%

In-app purchases

1 purchases

Peak Flow Log

One-time1
  • Peak Flow Log Plus$0.99
2 purchases

Peak Flow Diary | Asthma

Subscriptions2
  • Monthly Plan14 Days trial$3.991 Month
  • Annual Plan14 Days trial$24.991 Year

Questions

Is Peak Flow Log free?
Peak Flow Log is free to download, with in-app purchases available.
Is Peak Flow Diary | Asthma free?
Peak Flow Diary | Asthma is free to download, with in-app purchases available.
Which has better reviews, Peak Flow Log or Peak Flow Diary | Asthma?
Peak Flow Log is rated higher. Peak Flow Log averages 5.0 out of 5 from 1 ratings, while Peak Flow Diary | Asthma averages 4.7 from 36 ratings.
Do Peak Flow Log or Peak Flow Diary | Asthma have ads?
Peak Flow Diary | Asthma shows ads; Peak Flow Log does not.
Which is updated more often, Peak Flow Log or Peak Flow Diary | Asthma?
Peak Flow Log ships an update every 2 weeks, and Peak Flow Diary | Asthma every 3 weeks. Most recently, Peak Flow Log was updated on October 10, 2026 and Peak Flow Diary | Asthma on October 27, 2026.

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