Peak Flow Log: Asthma Diary

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, 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
- 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

Built to be trustworthy:

- Works fully offline. No account, no sign-in.
- Your data stays on your device. Nothing is uploaded.
- Export and import a backup so you never lose your history when changing phones.
- One-time purchase to unlock Pro. No subscription.

Free to log and see your zones. Pro unlocks the doctor PDF, unlimited profiles, full 90-day and all-time trends, and custom zone thresholds.

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. Always follow the asthma action plan given by your doctor, and seek medical help in an emergency.