Android app · Utility

Smooth-Mo

Motion and smoothness utility for tuning or exploring Android device behavior.

Get it on Google Play ↗ Source on GitHub ↗

Smooth-Mo is an Android app for creating smoother slow-motion video exports on device. It helps mobile creators pick a local video, choose an output frame-rate target, monitor background processing, and preview or share the result. The repository also includes Google Play listing assets for release preparation.

Project Overview

Smooth-Mo targets people who want quick mobile video smoothing without sending footage to a remote service. The app uses Jetpack Compose for the workflow, Room for local job history, Media3 for result preview, and WorkManager foreground work for longer processing jobs. A sibling Smooth-Mo-pv repository in the parent workspace provides the static privacy policy site used for Google Play and Netlify deployment.

Key Features

• 🎬 Import local videos through Android's system media picker and content URI flow.
• ⚙️ Configure 60 FPS or 120 FPS output targets before starting a processing job.
• 🐢 Enable 2x to 4x slow-motion mode with timestamp stretching for video samples.
• 🔔 Track foreground WorkManager progress with in-app stages and system notifications.
• 💾 Persist queued, processing, completed, and failed jobs with Room.
• ▶️ Preview completed results with AndroidX Media3 ExoPlayer.
• 📤 Export completed MP4 files into Movies/SmoothMo through MediaStore.

Architecture Overview

The app follows a small clean-architecture layout:

• presentation contains Compose screens, navigation, ViewModels, UI state, and share actions.
• domain contains video job models, repository contracts, scheduler contracts, and use cases.
• data contains Room persistence, metadata extraction, WorkManager scheduling, interpolation hooks, and output writing.
• play-store contains release artwork and listing text for Google Play preparation.

Request and data flow:

1. The user picks a video and chooses interpolation settings.
2. EnqueueJobUseCase stores a VideoJob in Room and schedules unique WorkManager work.
3. InterpolationWorker reads the job, updates progress, writes a cache MP4 result, and marks the job complete.
4. The result screen observes Room, previews the output, and exports it to Movies/SmoothMo when requested.

Design patterns include repository interfaces, use-case classes, a simple application container, Room type converters, foreground WorkManager jobs, and Compose state collection through ViewModels.

Tech Stack & Libraries

Configuration

Android app configuration lives in:

• app/build.gradle.kts for package name, SDK versions, signing, Compose, and dependencies.
• gradle/libs.versions.toml for dependency and plugin versions.
• .env for values read by the Secrets Gradle Plugin.
• app/src/main/AndroidManifest.xml for permissions, the launcher activity, deep links, FileProvider, and foreground service metadata.

Most Gradle, manifest, dependency, and signing changes require a rebuild. Runtime permission changes may require uninstalling and reinstalling the app during local testing.

Usage / Quick Start

Build and Run the Android App

./gradlew :app:assembleDebug
./gradlew :app:installDebug

After installation, open Smooth-Mo on the device, choose a video, select 60 FPS or 120 FPS, optionally enable slow-motion, and start processing.

Run Tests Locally

./gradlew testDebugUnitTest

This runs the JVM, Robolectric, and Roborazzi tests under app/src/test.

Build Store Assets Into a Release Workflow

ls play-store

Use the checked-in feature graphic, app icon, phone screenshots, tablet screenshots, and listing-descriptions.md when preparing the Google Play listing.

API Reference

Not applicable. Smooth-Mo does not expose a public HTTP API, CLI API, SDK API, or local service endpoint.

The app does define internal Kotlin contracts in app/src/main/java/com/michael/smoothmo/domain/repository:

Internal deep link:

Parameters: jobId is the Room/WorkManager job identifier generated when a job is enqueued.

Errors: invalid or missing job IDs open the progress route without a matching observed job.

Testing

Unit and host-side Android tests:

./gradlew testDebugUnitTest

Instrumentation tests on a connected device or emulator:

./gradlew connectedDebugAndroidTest

Coverage command: Not configured. The repository does not include a JaCoCo, Kover, or Android coverage task.

Test locations and conventions:

• JVM, Robolectric, and Roborazzi tests live in app/src/test/java.
• Instrumented tests live in app/src/androidTest/java.
• Existing tests use JUnit 4 and behavior-focused Kotlin test names where helpful.
• Roborazzi screenshot tests write generated captures under the test screenshot output paths.

Deployment

Android App

Debug build:

./gradlew :app:assembleDebug

Release build:

KEYSTORE_PATH=/absolute/path/to/upload-key.jks \
STORE_PASSWORD="$STORE_PASSWORD" \
KEY_PASSWORD="$KEY_PASSWORD" \
./gradlew :app:assembleRelease

The release signing config expects key alias upload. Store distribution metadata and Play Console app setup are not fully automated in this repository.

Health check: install the APK, select a short local video, run a processing job, preview the result, export it, and verify that the output appears under Movies/SmoothMo.

Privacy Policy Site

Not applicable inside this app repository. The static privacy-policy site lives in the sibling Smooth-Mo-pv repository in the parent workspace and can be deployed separately to Netlify.

Docker and docker-compose: Not applicable. No Dockerfile or compose file is present.