Comparo - Android Price Comparison App

A complete Android application that compares grocery prices across Swiggy Instamart, Zepto, and Blinkit using headless WebViews to intercept API calls.

Download

Latest APK

You can download the latest compiled APK without needing Android Studio:

Option 1: From GitHub Actions (Latest Build)

1. Go to Actions tab
2. Click on the latest successful "Build Android APK" workflow run
3. Scroll down to "Artifacts" section
4. Download Comparo-APK-build-XXX
5. Extract the ZIP file to get the APK

Option 2: From Releases (Stable Versions)

1. Go to Releases page
2. Download the latest Comparo-vX.X.X.apk file

Installation

1. Download the APK file
2. Enable "Install from Unknown Sources" in your Android settings
3. Open the APK file and install
4. Grant necessary permissions when prompted

Note: This is a debug APK for testing purposes. You may see a warning about installing apps from unknown sources - this is normal for APKs not downloaded from the Play Store.

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Features

• Multi-Platform Price Comparison: Compare prices across Swiggy, Zepto, and Blinkit simultaneously
• Headless WebView Architecture: Uses hidden WebViews to intercept API calls without breaking platform functionality
• Modern UI: Built with Jetpack Compose and Material 3 design
• Smart Product Grouping: Groups similar products from different platforms for easy comparison
• Price Highlighting: Automatically highlights the cheapest option with visual indicators
• Login Management: Secure login flow for each platform with cookie persistence
• Real-time Search: Search across all platforms with a single query
• Delivery Time Display: Shows estimated delivery time for each platform

Architecture

Core Components

1. NetworkInterceptor (interceptor/NetworkInterceptor.kt)

   • Extends WebViewClient to intercept API requests
   • Clones requests using OkHttp with proper headers
   • Returns null to allow original WebView requests
   • Parses JSON responses and broadcasts to MainActivity

2. PlatformParser (parser/PlatformParser.kt)

   • Parses JSON responses from all three platforms
   • Extracts product information (name, price, ETA, stock status)
   • Handles platform-specific data structures
   • Filters out-of-stock items

3. MainActivity (MainActivity.kt)

   • Manages three headless WebViews (one per platform)
   • Handles platform login dialogs
   • Coordinates search across all platforms
   • Updates UI state with search results

4. Jetpack Compose UI (ui/ComparoApp.kt)

   • SetupScreen: Platform login interface
   • HomeScreen: Search interface and results display
   • ComparisonCard: Individual product price comparison

Technical Stack

• Language: Kotlin
• UI Framework: Jetpack Compose with Material 3
• Networking: OkHttp for API request cloning
• WebView: AndroidX WebKit for modern WebView support
• Async: Kotlin Coroutines for background operations
• Min SDK: 24 (Android 7.0)
• Target SDK: 34 (Android 14)

Dependencies

- androidx.core:core-ktx:1.12.0
- androidx.compose:compose-bom:2024.01.00
- androidx.compose.material3:material3
- androidx.activity:activity-compose:1.8.2
- com.squareup.okhttp3:okhttp:4.12.0
- kotlinx-coroutines-android:1.7.3
- androidx.webkit:webkit:1.9.0

How It Works

1. Login Phase: Users log into each platform (Swiggy, Zepto, Blinkit) through WebView dialogs. Cookies are saved for session persistence.

2. Search Phase: When a user searches for a product:

   • The query is sent to all three headless WebViews simultaneously
   • Each WebView loads the respective platform's search page
   • NetworkInterceptor detects and clones API calls
   • JSON responses are parsed by PlatformParser
   • Results are aggregated and displayed in the UI

3. Comparison: Products are grouped by name, sorted by price, and displayed with the cheapest option highlighted.

File Structure

app/src/main/
├── AndroidManifest.xml
├── java/com/sohan/comparo/
│   ├── MainActivity.kt
│   ├── interceptor/
│   │   └── NetworkInterceptor.kt
│   ├── parser/
│   │   └── PlatformParser.kt
│   └── ui/
│       ├── ComparoApp.kt
│       └── Theme.kt
└── res/
    └── values/
        └── strings.xml

Building

./gradlew assembleDebug

Running

./gradlew installDebug

Security & Privacy

• Uses cleartext traffic for HTTP debugging (can be disabled for production)
• WebView debugging enabled for development
• Cookies stored locally on device
• No data sent to external servers

Future Enhancements

• Price history tracking
• Push notifications for price drops
• Favorites/wishlist functionality
• Share comparison results
• Dark mode support
• Product image display
• Additional platform support

License

This is a demonstration project for educational purposes.

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Built by M Sai Sohan (@sohan-a11y)

If you find this project useful, please consider giving it a ⭐ on GitHub!