Health Calculator – A Comprehensive Wellness App

Health and fitness are essential aspects of daily life, and technology plays a significant role in making health management more accessible. To contribute to this space, I developed a Health Calculator app using Flutter with GetX for state management and navigation. This app serves as a one-stop solution for individuals looking to track and improve their health through various essential health metrics, including:

• BMI (Body Mass Index) Calculator

• IBW (Ideal Body Weight) Calculator

• BFP (Body Fat Percentage) Calculator

• BMR (Basal Metabolic Rate) Calculator

With an intuitive interface, in-app purchases, and ad support, this app provides users with a comprehensive health tracking experience while generating revenue through premium features and ad monetization.

Project Overview

This health calculator app is designed for individuals who want to monitor their health metrics easily. Whether users are looking to track their weight, measure body fat percentage, or calculate their daily calorie needs, this app provides accurate and reliable results based on industry-standard formulas.

The application is built with Flutter, ensuring smooth cross-platform performance on both Android and iOS. I implemented GetX for efficient state management and navigation, which provides a lightweight yet powerful framework to ensure fast loading times and seamless user interactions.

Key Features

1. BMI Calculator (Body Mass Index)

• Determines whether a person is underweight, normal, overweight, or obese based on their height and weight.

• Uses the standard BMI formula to provide accurate results.

• Provides health insights and tips based on the BMI category.

• Allows users to track their BMI history over time.

2. IBW Calculator (Ideal Body Weight)

• Calculates the optimal body weight based on height and gender.

• Uses standard formulas such as the Devine, Robinson, and Miller equations.

• Helps users set realistic weight loss or weight gain goals.

3. BFP Calculator (Body Fat Percentage)

• Estimates body fat percentage using BMI, age, gender, and body measurements.

• Provides insights into healthy body fat ranges for men and women.

• Assists fitness enthusiasts and health-conscious users in monitoring fat loss.

4. BMR Calculator (Basal Metabolic Rate)

• Calculates the calories burned at rest based on age, weight, height, and gender.

• Helps users understand how many calories they need to maintain or lose weight.

• Offers personalized diet and exercise recommendations.

5. In-App Purchases & Ads

• The app offers premium features through in-app purchases, allowing users to unlock advanced features like personalized health insights, diet plans, and progress tracking.

• Integrated Google AdMob ads to generate revenue from free users while keeping the app accessible to all.

6. User-Friendly UI & Seamless Experience

• A clean, modern, and easy-to-use interface designed for all age groups.

• Dark Mode support for enhanced usability.

• Supports metric and imperial units, allowing users from different regions to input their data easily.

Technology Stack & Development Approach

1. Flutter with GetX for State Management & Navigation

• Used GetX for fast, efficient, and minimalistic state management.

• Ensured seamless navigation between screens with GetX’s routing system.

• GetX provided lightweight controllers, reducing app load time and memory usage.

2. Formulas & Algorithms

• Implemented scientifically backed formulas for BMI, IBW, BFP, and BMR.

• Used real-time calculations to provide instant results.

• Allowed users to adjust parameters dynamically for better accuracy.

3. Firebase & AdMob Integration

• Firebase Analytics for tracking user engagement and behavior.

• AdMob for monetization, ensuring a non-intrusive ad experience.

• Implemented Firebase Remote Config for A/B testing different UI and pricing models.

4. In-App Purchases (IAP)

• Used Google Play Billing and Apple In-App Purchase system for seamless transactions.

• Designed a tiered pricing structure, offering both one-time purchases and subscriptions.

• Integrated local currency support for better user reach.

Challenges & Solutions

1. Ensuring Accurate Health Calculations

• Problem: Different sources use slightly different formulas for BMI, IBW, BFP, and BMR.

• Solution: Implemented multiple calculation methods and allowed users to switch between formulas based on their preferences.

2. Keeping the App Lightweight & Fast

• Problem: The app needed to perform real-time calculations without affecting performance.

• Solution: Used GetX’s efficient memory management, keeping the app fast and responsive.

3. Optimizing Ad Placements Without Affecting User Experience

• Problem: Users might find ads intrusive, leading to a poor experience.

• Solution: Implemented smart ad placements, including rewarded ads for unlocking features instead of forcing users to watch them.

4. Ensuring Seamless Cross-Platform Functionality

• Problem: UI inconsistencies and different behaviors on Android and iOS.

• Solution: Used Flutter’s adaptive UI techniques to create a consistent experience on both platforms.

User Impact & Benefits

1. Promotes Health Awareness & Better Lifestyle Choices

• Users can track and monitor their BMI, IBW, BFP, and BMR in one app.

• Helps users understand their body metrics and make informed health decisions.

2. Encourages Weight Management & Fitness Goals

• Provides realistic goals for weight loss, weight gain, and maintaining a healthy body fat percentage.

• Helps users calculate daily calorie intake to maintain a healthy diet.

3. Accessibility for Global Users

• Supports multiple unit systems (metric & imperial).

• Works offline, allowing users to access their health data anytime, anywhere.

4. Free & Premium Access

• Free version allows basic health calculations with ad support.

• In-app purchases unlock premium features for advanced health tracking and insights.

My Role & Contributions

As the sole developer of this project, I handled:

• UI/UX Design – Created a minimal, user-friendly interface.

• State Management – Implemented GetX for efficient state handling.

• Backend & Data Management – Integrated Firebase for analytics and AdMob for ads.

• Algorithm Implementation – Researched and applied scientifically accurate health formulas.

• Monetization Strategy – Set up Google Play Billing & AdMob for revenue generation.

Conclusion

The Health Calculator app is a powerful yet lightweight health tracking tool, designed to help users monitor their body metrics and maintain a healthy lifestyle. With features like BMI, IBW, BFP, and BMR calculators, it provides users with essential health insights in a simple and intuitive format.

Built with Flutter and GetX, the app delivers smooth performance, fast calculations, and a seamless user experience. The integration of in-app purchases and ads ensures sustainability while keeping the app accessible to a wider audience.

This project highlights my expertise in Flutter, GetX, real-time calculations, in-app purchases, and monetization strategies, making it a standout addition to my portfolio.