ScrollIt (Internal Samsung Auto-Scroll Tool)

ScrollIt is a Kotlin Android app for internal use on Samsung phones. It provides:

1. Main app screen for permission setup and advanced tuning.
2. Floating overlay for runtime control of downward auto-scroll in other apps.

Download APK

ScrollIt can now be downloaded directly from GitHub Releases.

• Current stable release: ScrollIt v1.0.0
• Direct APK download: scrollit-v1.0.0-debug.apk
• Published: August 12, 2026
• Package: debug-signed APK for direct testing outside Google Play

What the app does

• Offers two separate scroll modes:
  • Touch is the default. It uses Android Accessibility and works without Shizuku.
  • AutoScroll uses Shizuku to hold one system-level touch and move it every 16 ms. This gives Android apps a continuous scroll stream similar to Windows middle-click scrolling.
• Shows only the permissions required by the selected mode.
• Opens the exact Android settings screens needed to enable permissions.
• Starts a floating, draggable overlay above other apps.
• Keeps the existing Accessibility gesture engine as the simple fallback.
• Uses 30 persistent speed levels, calibrated for slow continuous scrolling.
• Collapses into a small edge bubble and expands back on tap.

Required permissions

1. Draw over other apps (SYSTEM_ALERT_WINDOW)
2. One scroll backend:
   • Touch mode: Accessibility service (ScrollIt Accessibility)
   • AutoScroll mode: Shizuku running and ScrollIt authorized
3. Foreground service (overlay runs as foreground service)

Shizuku AutoScroll setup

Touch mode needs no Shizuku. Use the steps below only for AutoScroll. AutoScroll uses a continuous touch stream because many Android apps ignore mouse-wheel events, including Ultimate Guitar Tabs.

1. Install Shizuku from the official download page.
2. On Android 11 or newer, enable Developer options and Wireless debugging.
3. Open Shizuku. Under Start via Wireless debugging, tap Pairing and follow its pairing notification.
4. Return to Shizuku and tap Start. The top status must say that Shizuku is running.
5. Open ScrollIt and select AutoScroll.
6. Under Setup, tap Set up Shizuku and allow ScrollIt in the Shizuku permission dialog.
7. Allow Floating controls, open the controls, and press Start.

Non-root Shizuku must be started again after every phone restart. If Shizuku is stopped or access is denied, ScrollIt shows a red message and does not silently switch modes. The official illustrated instructions are in the Shizuku user manual.

Build APK

Note: this repository uses text-only launcher scripts (gradlew, gradlew.bat) that call a local Gradle installation.

Windows (recommended)

cd C:\Users\teply\Documents\scrollit
.\gradlew.bat testDebugUnitTest assembleDebug lintDebug

Linux/macOS

cd /workspace/scrollit
./gradlew testDebugUnitTest assembleDebug lintDebug

Expected APK path

• Relative: app/build/outputs/apk/debug/app-debug.apk
• Example absolute (Linux in this repo): /workspace/scrollit/app/build/outputs/apk/debug/app-debug.apk
• Example absolute (Windows): C:\Users\teply\Documents\scrollit\app\build\outputs\apk\debug\app-debug.apk

GitHub Releases

This repository now publishes installable APK files from GitHub tags that start with v.

Current release

1. GitHub release page: v1.0.0
2. Downloaded asset name: scrollit-v1.0.0-debug.apk
3. Release channel: stable

How new releases are published

1. Push the commit to main
2. Create a version tag such as v1.0.1
3. Push the tag to GitHub
4. GitHub Actions builds the APK and attaches it to the matching release

USB install via ADB

adb devices
adb install -r C:\Users\teply\Documents\scrollit\app\build\outputs\apk\debug\app-debug.apk

Samsung setup

Enable Developer options

1. Settings → About phone → Software information
2. Tap Build number 7 times

Enable USB debugging

1. Settings → Developer options
2. Enable USB debugging
3. Connect USB and confirm RSA key prompt

Enable overlay permission

1. Open ScrollIt
2. Tap Open overlay permission settings
3. Enable Appear on top for ScrollIt

Enable accessibility service

1. Open ScrollIt
2. Tap Open accessibility settings
3. Accessibility → Installed apps → ScrollIt Accessibility
4. Enable service and confirm warning dialogs

How to test all features

1. Open ScrollIt and select Touch or AutoScroll.
2. Check that Floating controls and the selected backend are On.
3. Choose a speed from 1..30; optionally expand Motion details.
4. Tap Open controls.
5. Drag overlay to desired place.
6. Tap Start on a long page.
7. Verify the page scrolls downward continuously.
8. Tap + and -:
   • speed number updates 1..30
   • change applies while scrolling is already running
9. Tap Stop and verify scrolling stops immediately.
10. Tap Hide and verify the bubble appears on the screen edge.
11. Tap the bubble and verify the overlay expands back.
12. Tap Exit and verify the overlay and foreground notification close.
13. Disable the selected backend and tap Start again. Verify a red error message appears and no fallback starts.

Known limitations

• Some apps/screens ignore injected accessibility gestures.
• AutoScroll uses touch injection because many Android apps ignore mouse-wheel events.
• AutoScroll requires Shizuku because ordinary Android apps cannot inject system input events.
• Gesture behavior differs slightly across One UI versions.
• Exact smoothness depends on app rendering and refresh timing.
• connectedDebugAndroidTest needs emulator or physical device.

Project structure (key files)

app/src/main/java/cz/teply/scrollit/
  MainActivity.kt
  OverlayService.kt
  ShizukuAutoScrollEngine.kt
  ShizukuInputUserService.kt
  TouchScrollProfileFactory.kt
  ScrollAccessibilityService.kt
  ScrollSettings.kt
  ScrollSettingsStore.kt
  ScrollSpeed.kt

app/src/main/res/layout/
  activity_main.xml
  overlay_controls.xml
  overlay_bubble.xml

app/src/main/res/xml/
  scroll_accessibility_service.xml

License

MIT. See LICENSE.