MigsScan

A no-frills Android document scanner. Open the app, tap Scan, point your phone at the page, share the result as a PDF (or JPEG / PNG). No ads, no sign-in, no cloud upload, no "premium" tier.

The actual scanning — edge detection on creased and folded paper, perspective correction, multi-page batching — is handled by Google's on-device ML Kit document scanner, so the magic is the same one Google Drive uses. This app is just a thin wrapper around it: launch the scanner, save the result, share.

Features

• Capture single or multi-page scans (up to 50 pages per document)
• Automatic edge detection and perspective correction
• Import existing photos from the gallery instead of capturing live
• Share each scan as PDF, JPEG, or PNG via the standard Android share sheet (Gmail, Drive, Messages, AirDrop-equivalents, anything) — with real thumbnails of the scan in the chooser preview
• Quick-send presets — register tiles like "Email to dad" or "Send to WhatsApp" that skip the OS chooser and pre-fill recipients
• Rename any scan — the new name is what Gmail, Drive etc. see as the attached file's name
• OCR text search — extracted text from every page is indexed, so the search bar finds scans by their content even if you never renamed them
• Auto-suggested names from OCR — the rename dialog offers the first meaningful line on page 1 as a one-tap suggestion
• Star scans to pin them to the top of the list
• Tap a row for a full-screen preview with pinch-to-zoom + horizontal swipe through every page
• Edit pages within a scan — reorder, delete a page, or append new ones
• Long-press a row to enter selection mode and bulk-delete several scans
• Settings: choose between the full ML Kit editor and a one-snap quick capture, set a default share format
• Backup to any folder via Android's Storage Access Framework — works with Google Drive, Dropbox, OneDrive, local storage, USB; the user picks once, the app mirrors scans there
• Thumbnails of the first page on every row
• Scans persist between launches on local storage
• Adaptive launcher icon, branded splash, light + dark mode

Not (yet) in the app

• Folders / tags
• Cloud sync handled directly by the app (use SAF backup to a Drive folder instead — same effect, no provider lock-in)
• Auto-scheduled backup (WorkManager) — backup is manual-trigger for now

Requirements

• Android 7.0 (API 24) or newer
• Google Play Services on the device (the ML Kit document scanner module is downloaded through Play Services on first use — comes pre-installed on every consumer Android phone)

Build & install

The project is a standard Gradle Android build. You need:

• JDK 17 or 21 (the bundled gradlew script picks up whatever java you point JAVA_HOME at; Android Studio's JBR works out of the box)
• Android SDK with platform 35 + build-tools 35 (Android Studio installs these by default)

./gradlew :app:assembleDebug      # build a debug APK
./gradlew :app:installDebug       # install on a connected device

The debug APK lands in app/build/outputs/apk/debug/.

Tests

./gradlew :app:testDebugUnitTest          # local JVM + Robolectric (no device)
./gradlew :app:pixel6api36DebugAndroidTest  # on-device suite on a managed headless emulator
./gradlew :app:connectedDebugAndroidTest  # on-device suite against a plugged-in phone

The pixel6api36 device is provisioned automatically the first time you run it (a google_apis_playstore system image is downloaded — ~1 GB). After that runs are fast and offline.

Suite	Files	What it covers
Local	ScanStoreTest, ShareFormatTest, SharingTest, ScanViewModelTest	persistence, intent shape, PNG re-encode cache, ViewModel state
On-device	SharingFileProviderTest, MigsScanAppUiTest, ScanFlowEndToEndTest	real FileProvider URIs, Compose screens, scan → persist → share round-trip

The local suite runs in CI on every push; the on-device suite is intended to run against a plugged-in phone or an emulator.

Tech stack

• Kotlin 2.1 + Jetpack Compose (Material 3)
• CameraX-free — all capture goes through ML Kit's play-services-mlkit-document-scanner, which launches its own polished scanner UI
• AndroidX FileProvider for share-sheet URIs
• Robolectric + JUnit 4 locally, Compose ui-test-junit4 on-device

Project layout

app/
  src/main/java/dev/migs/scan/
    MainActivity.kt              # hosts the Compose tree
    data/                        # Scan, ScanPayload, ScanStore
    share/                       # ShareFormat, Sharing (intent builders)
    ui/                          # MigsScanApp, ScanViewModel, ScannerLauncher
  src/test/                      # local JVM / Robolectric suite
  src/androidTest/               # on-device suite
tools/icon.svg                   # source for the launcher icon (re-export with ImageMagick)
.github/workflows/ci.yml         # build + unit tests on every push