NerdCalci

Fully offline Android calculator app for power users with variable support, syntax highlighting, file-based sessions, and more.

Screenshots

Features

Smart Calculations

• Variable Support: Define variables and use them in calculations

  a = 100
  b = 200
  total = a + b  # 300
  

• Percentage Calculations: Natural percentage syntax

  20% of 50000    # 10000
  15% off 1000    # 850
  50000 + 10%     # 55000
  50000 - 5%      # 47500
  

• Comments: Add notes with # symbol

  price = 1000  # base price
  tax = 18% of price  # 180
  

• Mathematical Functions: Built-in support for common math functions (see exp4j documentation for more details)

  sqrt(16)           # 4
  sqrt 16            # 4
  sin(pi/2)          # 1
  log10(1000)        # 3
  pow(2, 8)          # 256
  abs(-42)           # 42
  
  # Calculate circle area
  radius = 5
  area = pi() * pow(radius, 2)  # 78.54
  
  # Convert degrees to radians and calculate sine
  degrees = 45
  radians = degrees * pi / 180
  result = sin(radians)  # 0.71
  
  # Exponential growth
  principal = 1000
  rate = 0.05
  time = 10
  amount = principal * exp(rate * time)  # 1648.72
  

Editor Features

• Syntax Highlighting: Color-coded variables, numbers, operators, and comments
• Auto-completion: Smart variable suggestions as you type
• Line Numbers: Easy reference and navigation

File Management

• Multiple Files: Create and manage separate calculation files
• Auto-save: Changes are saved automatically
• Pin Files: Keep important files at the top (max 10 pinned files)
• Duplicate Files: Create a copy of a file with a new name
• Backups: Automatically or manually backup your files to app storage or a custom folder
• Restore from backups: Restore your files from backups
• Copy with Results: Copy file content with calculated results to clipboard

And More...

• Offline: Works without internet
• Undo/Redo: Up to 30 steps per file
• Dark/Light Theme: System, dark, or light mode
• Real-time Results: See calculations update as you type

Download/Install

From F-Droid (Recommended)

Submission in progress - will be available soon!

From Obtainium

You need to install Obtainium first on your Android device.

From GitHub Releases

1. Go to the Releases page
2. Download the latest APK file
3. Transfer to your Android device
4. Enable "Install from Unknown Sources" if prompted
5. Open the APK and install
6. Start calculating!

From Source

1. Clone the repository:

   git clone https://github.com/vishaltelangre/NerdCalci.git
   cd nerdcalci

2. Open the project in Android Studio

3. Build and run on your device or emulator

Built With

• Kotlin - Primary programming language
• Jetpack Compose - Modern UI toolkit
• Room Database - Local data persistence
• Material Design 3 - UI components and theming
• exp4j - Mathematical expression evaluation
• Fira Code - Monospace font with ligatures

Development

Running Tests

Run all unit tests:

./gradlew :app:testDebugUnitTest

Run specific test class:

./gradlew :app:testDebugUnitTest --tests "com.vishaltelangre.nerdcalci.core.MathEngineTest"

After running tests, view the HTML report:

open app/build/reports/tests/testDebugUnitTest/index.html

Generate App Icons

Automatically generate all required app icon sizes from a single source image:

./scripts/generate-icons.sh ~/Downloads/app-icon.png

This creates:

• Android mipmap icons (mdpi, hdpi, xhdpi, xxhdpi, xxxhdpi)
• Fastlane metadata icon
• Both regular and round launcher icons

Requirements:

• Source image: PNG, minimum 512x512 (recommended: 2048x2048)
• Square aspect ratio (1:1)
• macOS: sips (built-in) or ImageMagick

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the project
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License

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