# Gut health tracking app

> App for iOS and Android with daily logging, a health score, video courses, store subscriptions and AI photo classification.

Source: https://boosting.tech/en/case-studies/health-app/
The client is not named. We describe the sector, the problem and what was built.

**Case summary:** A nutrition professional wanted to turn the follow-up she did in her practice into a digital product. We built an app for iOS and Android in which the user logs bowel movements and symptoms, gets a weekly score and watches courses. An AI model classifies the photo the user sends on a clinical scale.

- Sector: Digital health and nutrition
- Users: Patients and the general public
- Platform: App for iOS and Android, API and admin panel
- Technology: React Native, Expo, Ruby on Rails, PostgreSQL
- Evolving since: 2025

## What the system does

- Daily logging on the Bristol scale
- Symptoms of the day with intensity
- Health score for the last seven days
- Photo classification by a vision model
- Video courses with progress
- Subscription through the App Store and Google Play
- Sign in with email and with Apple
- Onboarding questionnaire

## What was the problem?

In a practice, gut health follow-up depends on what the patient remembers between one appointment and the next. A paper diary tends to be abandoned within days. The professional wanted logging simple enough to become a habit, and useful also to people who would never be her patients.

## What was built?

An app for iOS and Android, an API and an admin panel. The user logs each bowel movement by visually picking one of the seven types on the Bristol scale, and adds color, size and symptoms. General symptoms of the day, such as bloating and cramps, go into a separate log.

With data from the last seven days, the app calculates a gut health score. A courses area has video lessons with progress tracking. Full access is by subscription, bought inside the stores.

## How does it work day to day?

Logging takes a few taps. Those who prefer can take a photo, and a vision model classifies the image on the Bristol scale and returns a short tip on diet or hydration. The model is instructed to ask for a better photo when it cannot assess the image, and never to give a diagnosis.

The onboarding questionnaire asks how long the person has had symptoms and which conditions are already known, and that adjusts what they see first.

## What changed?

The professional now has a product that works without her being present, and the patient brings a real history to the appointment instead of memories. The app keeps getting new versions.

This case brings together [apps](/en/services/mobile-apps/) and [AI and automation](/en/services/ai-and-automation/). The API uses the same base as our [custom web systems](/en/services/custom-web-systems/).

## Frequently asked questions about health apps

### Does the AI replace a professional's assessment?

No. It classifies an image on a known scale and suggests general care. The app gives no diagnosis and highlights the entries that call for a professional's attention.

### How is the subscription charged?

Through the App Store and Google Play, which handle payment and renewal. The app checks the subscription status to release the content.

### Does the same code serve iOS and Android?

Yes. The app is built in React Native with Expo, and both stores receive versions generated from the same base.