How is this different from a symptom tracker?

The central object is the pairing between an exposure and a reaction, not a symptom score over time. The exposure log, the known-allergens list with label photos, and the medication inventory with epinephrine expiry are what an allergist needs and what a general symptom tracker does not model.

Should the app suggest what the user is allergic to?

It can show which exposures most often preceded reactions, labelled plainly as a count, and leave the conclusion to the allergist. Do not phrase it as a diagnosis, do not rank "likely allergens", and keep the confirmed-by field so self-suspected and clinically confirmed allergens are never mixed in the report.

How to Build an Allergy Tracker App with AI (2026)

What a allergy tracker app needs

Reaction log with symptoms, severity, onset time, and what was taken
Exposure log: foods, products, environments, and medications in the hours before
Known allergens list with a photo of the ingredient label that caught you out
Medication inventory with expiry dates and reminders, especially epinephrine
Allergist report: reactions by month, top suspected triggers, export as PDF

The screens

Screen	What it does
Today	Quick-log buttons for reaction and exposure, next medication expiry, recent entries
Log Reaction	Pick symptoms, slide severity, set onset time, record treatment taken
Log Exposure	What, when, and where; recent items first for fast repeat entry
History	Timeline mixing reactions and exposures so the pairing is visible
Report	Date-range summary with reaction counts, severities, and suspected triggers, share as PDF

The data model

Reaction: startedAt, symptoms (array), severity (1-5), onsetMinutes (optional), treatment (array of medicationId), notes, photoUri (optional)
Exposure: occurredAt, kind (food | product | environment | medication), label, location (optional), notes
Allergen: name, kind, confirmedBy (self | allergist), labelPhotoUri (optional), notes
Medication: name, kind (antihistamine | epinephrine | inhaler | other), dose, expiresAt, remindDaysBefore
EmergencyCard: allergens summary, medications, emergency contact, physician

The build prompt (copy this)

Paste this into ShipNative and it becomes a working React Native app with these screens, navigable in a live preview, in about two minutes:

“An allergy tracker for people managing food, drug, or environmental allergies. Today shows two large quick-log buttons, Reaction and Exposure, the next medication expiring, and the latest entries. Logging a reaction means picking symptoms from a fixed list (hives, swelling, wheezing, GI, and others), sliding a severity from one to five, setting when it started, and ticking which medications were taken, with an optional photo and notes; the whole flow is designed to be done one-handed in under a minute. Logging an exposure records a food, product, environment, or medication with a time and optional place, with the most recent items offered first for repeat entry. History shows reactions and exposures on one timeline so what preceded a reaction is visible. Known allergens are kept in a list with an optional photo of the ingredient label and whether the allergen was confirmed by an allergist. Medications store dose and expiry date and fire a reminder a chosen number of days before expiry; epinephrine auto-injectors are highlighted. Report takes a date range and produces reaction counts by month, severity distribution, and the exposures that most often preceded reactions, exportable as a PDF to bring to an appointment. An emergency card screen shows allergens, medications, and an emergency contact, reachable from the lock-screen widget if the platform allows. Works offline; data stays on device unless the user exports. Screens: Today, Log Reaction, Log Exposure, History, Report.”

Then iterate with small, screen-specific prompts (“make the primary button bigger”, “add an empty state”), preview on your own phone, and export the full Expo project whenever you want. The full method: how to build an app with AI.

How it makes money

Free core logging with a one-time unlock ($5-10) for the PDF report and multi-profile support for parents tracking more than one child. Keep the emergency card and the medication expiry reminders free on every tier; charging for them is both wrong and the kind of thing that ends up in a one-star review. Say clearly that the app records, it does not diagnose, and that the "suspected triggers" are co-occurrence counts, not causation.

Implementation and the revenue math for every model: how to make money from an app. When you’re ready to ship: App Store and Google Play publishing guides.

Build it now

The prompt above is free to run at shipnative.dev — working allergy tracker app on your phone today, full code export.

How to Build an Allergy Tracker App with AI