Vital Health Application

A lightweight health tracking system built with Flutter

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Overview

This application provides a streamlined interface for tracking critical health metrics. It is designed for maximum simplicity and operates with minimal infrastructure overhead, utilizing Google Apps Script and Google Sheets for data management.

Screenshots

Main Interface	Data Entry	Settings

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Features

Health Tracking

Feature	Description
Weight Logging	Record daily weight measurements in kilograms with timestamped entries.
Blood Pressure	Log systolic and diastolic pressure levels through a structured interface.
Combined Actions	Simultaneously record weight and blood pressure for improved efficiency.

System Characteristics

Characteristic	Description
Minimalist UI	A home screen designed with exactly three primary actions to reduce cognitive load.
Serverless Integration	Direct communication with Google Apps Script to eliminate dedicated server maintenance.
Transparent Storage	Data is persisted in a Google Sheets spreadsheet for immediate user accessibility.
Configuration Persistence	Local storage of user preferences and backend endpoints via Shared Preferences.

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Tech Stack

Layer	Technology
Language	Dart 3.x
Framework	Flutter (Material 3)
State Management	Provider
HTTP Client	http package
Configuration	shared_preferences
Architecture	Google Apps Script (Web App)
Storage	Google Sheets

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Architecture

The application focuses on a direct communication model between the mobile client and the logic layer.

• Presentation Layer: Implements a simplified user interface centered on three core logging activities.
• Provider Layer: Manages configuration state and facilitates asynchronous data transmission.
• Logic Layer (Google Apps Script): Receives encrypted payloads and executes the write operations to the spreadsheet.
• Data Layer: Utilizes Google Sheets as the primary persistence mechanism.

lib/
├── core/                  # Application theme and constants
├── data/
│   ├── api_client.dart    # Apps Script communication logic
│   └── models.dart        # Weight and Blood Pressure data structures
├── presentation/
│   ├── providers/         # Configuration and Health data providers
│   └── screens/           # Home, Onboarding, and Settings screens
└── main.dart              # Application entry point

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Getting Started

Prerequisites

• Flutter SDK 3.x
• Google Account for spreadsheet hosting

Configuration

1. Backend Setup: Deploy the google_apps_script.js file found in the root directory as a Google Apps Script Web App.
2. App Setup: Launch the application and enter your name and the Web App URL during the onboarding process.
3. Permissions: Ensure the Web App deployment is configured to allow access to the target spreadsheet.

Build and Run

flutter pub get
flutter run

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Design Principles

• Typography: Utilizes the Material 3 type scale with Inter and Playfair Display for clear readability.
• Visual Style: A professional light and dark mode palette that avoids high-contrast fatigue.
• Simplicity: Every interaction is designed to get the user to the log completion screen in the fewest steps possible.

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License

This project is licensed under the GNU General Public License v3.0 — see the LICENSE file for details.