Asthma Tracker: Peak Flow Log

Peak Flow Log turns your daily peak-flow reading into a clear picture you and your doctor can act on.

Blow into your own peak-flow meter, type in the number (or your three blows — the best is kept), and the app instantly shows your zone as a percentage of your personal best:

- GREEN, YELLOW or RED at a glance, based on your own numbers
- Log reliever (rescue) inhaler puffs, symptoms and triggers in one tap
- Daily preventer: tick off each morning and evening dose on the Today screen and see your last 7 days as dots
- Morning and evening reminders for readings and for your preventer, quiet once you've logged
- Write your peak flow and reliever puffs to Apple Health
- See your trend over time with clear color-coded zone bands
- Track more than one person, so parents can follow their child too
- Create a clean PDF report to share at every appointment

Pro (one-time purchase, no subscription):

- Preventer adherence for the last 30 and 90 days, with a weekly trend in History and in the doctor PDF
- Doctor PDF with morning–evening variability and your action plan
- Your own action plan: write what your doctor told you to do in each zone and see it the moment a reading lands there
- Reliever doses left: your canister counts down from the puffs you already log, with a warning before it runs out
- Home-screen widget with your latest zone and whether you've logged today
- Unlimited profiles, full 90-day and all-time trends, trigger insights, custom zone thresholds

Built to be trustworthy:

- Works fully offline. No account, no sign-in.
- Your data stays on your device. Nothing is uploaded. Health is write-only — the app never reads your Health data.
- Export and import a backup so you never lose your history when changing phones.

Peak Flow Log records and visualizes readings you take with your own meter. It does not diagnose, treat, or provide medical advice, and it is not a medical device. Zones are based on a percentage of your personal best that you or your clinician set, and the action plan is text you enter yourself. Always follow the asthma action plan given by your doctor, and seek medical help in an emergency.