Catcha is an interactive Android application built using Jetpack Compose designed to help resolve everyday dilemmas in a playful and engaging way. Featuring a hand-drawn school notebook theme with crayon aesthetics, the app turns mundane decisions into satisfying, tactile, and visual experiences.
| Splash Screen | Main Menu | Finger chooser | finger grouper | finger order |
|---|---|---|---|---|
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Below is an overview of the decision-making tools included in Catcha:
| Feature Name | Input Method | Customization Options | Primary Visual Style | Haptic & Sound Effects |
|---|---|---|---|---|
| Finger Chooser | Multi-touch (Fingers) | Number of winners (1 to 4), Minimum fingers (2 to 6) | Expanding ripples, shrinking countdown arc, and a spring-physics spotlight reveal | Pop sound effects, countdown tick vibrations, and a strong winner haptic pulse |
| Finger Grouper | Multi-touch (Fingers) | Number of groups (2 to 4), Minimum fingers (3 to 6) | Sketchy hand-drawn crayon connector lines and handwritten floating group bubbles | Pop sound effects, countdown haptic ticks, and a final grouping vibration |
| Finger Order | Multi-touch (Fingers) | Minimum fingers (2 to 10 via a dropdown) | Numbers inside circles, floating ordinal bubble labels, and sketched dashed sequence paths | Pop sound effects, countdown haptic ticks, sequential order reveal vibes |
- Real-time Multi-touch Pointer Tracking: Place multiple fingers on the screen simultaneously. Each finger is tracked with a sketchy gray core, double outlines, and expanding animated ripple waves.
- Customizable Winner Count: Choose how many players to pick randomly (from 1 to 4) using the floating control panel at the top.
- Visual Shrinking Countdown: A thick border shrinks around each finger during a 4-second countdown, indicating when the decision will trigger.
- Spotlight Celebration Reveal: Selected winning fingers remain highlighted with a spring-physics scaling pulse (beating scale), while the rest of the screen is overlaid with the winner's harmonic crayon tint, hiding non-selected areas.
- Balanced Team Division: Automatically divide active players evenly into balanced teams (supporting up to 4 teams).
- Hand-Drawn Connecting Paths: Players in the same team are connected by hand-drawn sketchy crayon lines, rendering multiple jittery strokes for a real penciled look.
- Handwritten Balloon Labels: Each player's finger displays a floating handwritten box indicating their team (e.g., "GROUP 1", "GROUP 2").
- Flexible Configuration: Choose your desired team count (2 to 4) and minimum participants instantly before starting.
- Random Turn Sequence: Touch together to generate a random turn order from 1 to N players.
- Sequential Path Connection: Draws sketched black dashed connecting arrows between the fingers following the generated order (e.g., 1 -> 2 -> 3).
- Ordinal Balloon Labels: Floating handwritten bubbles appear above each finger showing their exact sequence position (e.g., "1st", "2nd", "3rd").
- Compact Dropdown Configuration: Choose the minimum required fingers (from 2 to 10) easily using a compact dropdown menu at the top.
- Persisted Finger Colors: Once the order is determined, circles maintain their distinct assigned crayon colors even if fingers are lifted from the screen.
- Polished Entrance Animation: The Catcha logo enters the screen with a combined fade-in and scale-bounce animation.
- Doodle Styling: Features a hand-drawn double-bordered box around the logo and a crayon-red zigzag accent under the title text.
Catcha is meticulously styled to look and feel like an interactive, handwritten school notebook:
- Textured Notebook Paper Background: A warm creamy paper color (
ObsidianBg:0xFFFCFAF5) layered with faint blue-gray grid lines and a pink/red left margin line. - Background Sketch Doodles: Subtle, low-opacity drawings (a smiling cloud, a scribble star, paper binding loops, and a happy face) are scattered in the background.
- Thick Charcoal Outlines: Interactive buttons, cards, text inputs, and dialogs are bordered with thick, ink-black lines (
BorderColor:0xFF121212) representing charcoal pen strokes. - 3D Solid Shadows: Cards and buttons utilize flat, solid-black offsets to the bottom-right for a playful, cartoon/comic book depth.
- Bubble SFX Engine: Interacting with buttons, cards, and starting games triggers playful, satisfying bubble-pop audio effects.
- Handwritten Typography System:
- Cabin Sketch (Bold): Used for all large title components, headers, countdown numbers, and status states, giving them a rich hand-shaded hatching look.
- Cabin (Medium/SemiBold/Bold): Used for secondary text, descriptions, lists, and dialog bodies, ensuring maximum readability while maintaining a friendly, rounded handwritten feel.
- Font Weight Safeguard: All font weights are mapped correctly in the Compose typography system to prevent fallback to generic system fonts (like Roboto).
| Component | Technology / Detail |
|---|---|
| Programming Language | Kotlin (1.9.22) |
| UI Framework | Jetpack Compose with Material 3 |
| Design Theme | School Notebook Paper & Playful Crayon Doodle Art Theme |
| Typography System | Cabin Sketch (Titles) & Cabin (Clean text) - Bundled Offline |
| Sound Effects Engine | Bubble Sound Player (Android MediaPlayer API) |
| Haptic Feedback | Android OS Vibrator API |
| Dependency Management | Gradle Version Catalog (libs.versions.toml) |
| Build Parameters | Compile SDK 35, Min SDK 26 (Android 8.0) |
This project is built using Gradle and can be opened in Android Studio or compiled directly via the terminal.
- Java Development Kit (JDK) 17 or newer.
- Android SDK Platform API 34 or 35.
- Open your terminal or PowerShell in the root directory of the project, for example:
d:\Project\app\Catcha. - Run the following Gradle command to compile a debug APK:
.\gradlew.bat assembleDebug - Once the build completes, the compiled APK will be located at:
app/build/outputs/apk/debug/app-debug.apk - Copy the
app-debug.apkfile directly to your physical Android device to install and run it.
- Launch Android Studio, select Open Project.
- Navigate to the directory
d:\Project\app\Catcha. - Wait for the Gradle sync to complete successfully.
- Connect a physical Android device (with USB debugging enabled) or launch an Emulator.
- Click the green Run button to install and launch the application.
Catcha/
├── app/
│ ├── src/
│ │ └── main/
│ │ ├── kotlin/org/example/
│ │ │ ├── MainActivity.kt # State navigation and core app entry point
│ │ │ ├── audio/
│ │ │ │ └── BubbleSoundPlayer.kt # Bubble-pop sound effects manager
│ │ │ ├── components/
│ │ │ │ ├── DoodleComponents.kt # Handwritten & school notebook UI components
│ │ │ │ └── SparkleConfetti.kt # Canvas-based particle confetti system
│ │ │ ├── data/
│ │ │ │ └── AppSettings.kt # App state storage for audio/haptics settings
│ │ │ ├── screens/
│ │ │ │ ├── SplashScreen.kt # Animated entrance splash screen
│ │ │ │ ├── MainMenuScreen.kt # Notebook-themed home dashboard
│ │ │ │ ├── FingerChooserScreen.kt # Multi-touch pointer random chooser screen
│ │ │ │ ├── FingerGrouperScreen.kt # Multi-touch finger grouping screen
│ │ │ │ └── FingerOrderScreen.kt # Multi-touch random turn order screen
│ │ │ └── theme/
│ │ │ ├── Color.kt # Color definitions for Crayon & Notebook theme
│ │ │ ├── Theme.kt # Material 3 setup and Edge-to-edge configurations
│ │ │ └── Type.kt # Typography configurations and custom font families
│ │ └── res/
│ │ ├── values/
│ │ │ ├── strings.xml # Localization text keys
│ │ │ └── themes.xml # Native Android base themes configuration
│ │ ├── drawable/
│ │ │ ├── catcha_ico.png # Application logo icon
│ │ │ ├── ic_launcher_background.xml
│ │ │ └── ic_launcher_foreground.xml
│ │ └── font/
│ │ ├── cabin_bold.ttf # Clean handwriting bold
│ │ ├── cabin_medium.ttf # Clean handwriting medium (default normal weight)
│ │ ├── cabin_regular.ttf # Clean handwriting regular
│ │ ├── cabin_semibold.ttf # Clean handwriting semibold
│ │ └── cabin_sketch_bold.ttf # Sketchy hand-shaded bold (default sketch weight)
│ └── build.gradle.kts # Android module build and dependencies configuration
├── gradle/
│ └── libs.versions.toml # Centralized dependency Version Catalog
└── settings.gradle.kts # Gradle settings and module inclusions