Should the app tell the user when to go to the hospital?

Show the pattern, not a verdict. Display how the last hour compares with the 5-1-1 guideline and tell the user to follow their provider’s instructions, which often differ for second births, distance to hospital, or medical history. A hard "go now" message is both a liability and frequently wrong.

Why keep the screen awake?

Because the user taps the button every few minutes for hours and unlocking a phone mid-contraction is a real obstacle. Use expo-keep-awake only while a session is active and release it when the session ends, so the battery drain is bounded to the time it matters.

How to Build a Contraction Timer App with AI (2026)

What a contraction timer app needs

One full-screen button to start and stop a contraction
Live duration during a contraction, interval since the last one ended
History list with duration, interval, and intensity per contraction
Pattern signal showing progress toward 5-1-1 over the last hour
Share the log as text or PDF for the midwife or hospital

The screens

Screen	What it does
Timer	Huge start/stop button, current duration, time since last, 5-1-1 status strip
History	Reverse-chronological list of contractions with duration and interval columns
Contraction Detail	Edit start, end, and intensity; delete a mis-tap
Summary	Last-hour averages, chart of intervals, share button
Settings	Intensity scale on or off, haptics, keep screen awake, reset session

The data model

Session: startedAt, endedAt (optional), notes
Contraction: sessionId, startedAt, endedAt, intensity (1-5, optional)
Settings: intensityEnabled, hapticsEnabled, keepAwake

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:

“A contraction timer app for labour. The Timer screen is dominated by one very large button that starts a contraction on tap and stops it on the next tap; while a contraction is running it shows the live duration in large type, and between contractions it shows the time since the last one ended. Below the button a status strip evaluates the last sixty minutes against the 5-1-1 rule (contractions about five minutes apart, lasting about one minute, sustained for an hour) and shows plainly how close the pattern is, in words, not just numbers. Each contraction optionally gets an intensity from one to five chosen after it ends; no free-text typing anywhere in the core flow. History lists every contraction with duration and interval; tapping one opens a detail screen where start, end, and intensity can be corrected and a mis-tap deleted. Summary shows last-hour averages and a simple chart of intervals, with a share action that exports the log as text and PDF. Settings: intensity on or off, haptics on or off, keep screen awake while a session is active, and a clearly confirmed reset that starts a new session. Dark theme by default, huge touch targets, works fully offline. Screens: Timer, History, Contraction Detail, Summary, Settings.”

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, with a one-time unlock ($4-7) for export and the chart, or genuinely free as a lead-in to a larger pregnancy or baby app. Do not put the timer itself or the 5-1-1 signal behind a paywall; the audience is time-limited and stressed, and the reviews will say so. State plainly that the app is a timer, not medical advice, and tell users to call their provider.

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 contraction timer app on your phone today, full code export.

How to Build a Contraction Timer App with AI