Airplane Lock – Parental Control

An Android parental-control app that prevents a child from disconnecting or shutting down a monitored device. It watches for Airplane Mode, Mobile Data off, and Power-off / Restart actions, and blocks them behind a parental password. A separate short "travel / bypass" code lets the parent temporarily lift all restrictions (for example, on an actual flight).

Built for personal/parental use. Some capabilities require one-time setup via ADB (see Setup).

Features

• Airplane Mode lock – when airplane mode is turned on, a full-screen password prompt appears. The child must enter the parental password or turn airplane mode back off.
• Mobile Data lock – turning mobile data off triggers the same password prompt.
• Power-off / Restart lock – an accessibility service detects the system power menu (power off, restart, shut down) and requires the password to proceed.
• Travel / Bypass mode – a separate short code temporarily disables all restrictions; turning it back off requires the main parental password.
• Always-on Battery Saver – the app keeps battery saver enabled (requires WRITE_SECURE_SETTINGS, granted once via ADB) and silently re-enables it if turned off.
• Uninstall protection – optional Device Admin so the app cannot be uninstalled from Settings without first disabling Device Admin (which is password-protected).
• Brute-force protection – after 5 wrong password attempts the lock screen is disabled for 60 seconds.
• Activity Log (new) – every blocked airplane-mode, mobile-data and power-off attempt, plus failed unlocks, lockouts and bypass activations, is recorded with a timestamp. Parents can review the history (and clear it) from the main screen via View Activity Log. The log is capped at the 100 most recent events and stored locally in the app's private preferences.

Tech Stack

• Language: Java
• Platform: Android (minSdk 26 / Android 8.0+, targetSdk 34, compileSdk 34)
• Build system: Gradle (Android Gradle Plugin 8.2.0)
• Libraries: AndroidX AppCompat & Core; org.json (bundled with the Android platform)
• Key Android APIs: DeviceAdminReceiver, AccessibilityService, foreground Service, BroadcastReceiver, ContentObserver, Settings.Global

Setup

Prerequisites

• Android Studio (or Gradle + Android SDK)
• A device/emulator running Android 8.0 (API 26) or higher
• adb available on your PATH for the one-time secure-settings grant

Build & install

# From the project root
./gradlew assembleDebug
adb install app/build/outputs/apk/debug/app-debug.apk

Or simply open the project in Android Studio and press Run.

One-time ADB grant (for Battery Saver control)

adb shell pm grant com.parentalcontrol.airplanelock android.permission.WRITE_SECURE_SETTINGS

Usage

1. Open the app and set a parental password (minimum 4 characters).
2. (Recommended) Tap Activate Device Admin to prevent uninstallation.
3. Grant Display over other apps when prompted (needed to show the lock screen).
4. Enable the accessibility service in Android Settings to activate power-off blocking.
5. Optionally set a short bypass code for travel.
6. From now on, attempts to enable airplane mode, disable mobile data, or power off the device will require the parental password.
7. Tap View Activity Log at any time to see what was attempted.

Bypass / Travel mode

• On the lock screen, tap Use Travel / Bypass Code and enter the bypass code to temporarily disable all restrictions.
• To re-enable restrictions, open the app → Travel / Bypass Mode → Turn Bypass Mode OFF, then confirm with the main parental password.

The default bypass code shipped on first launch is documented in BYPASS_CODE.txt. Change it from the app's Travel / Bypass Mode section and keep it private.

Project Structure

AirplaneLock/
├── build.gradle                # Root Gradle config (AGP plugin)
├── settings.gradle             # Module includes
├── BYPASS_CODE.txt             # Default travel/bypass code & instructions
└── app/
    ├── build.gradle            # App module config & dependencies
    ├── proguard-rules.pro
    └── src/main/
        ├── AndroidManifest.xml
        ├── java/com/parentalcontrol/airplanelock/
        │   ├── MainActivity.java         # Setup UI: password, bypass, admin, activity log
        │   ├── PasswordActivity.java     # Full-screen lock prompt
        │   ├── MonitorService.java       # Foreground service: airplane/data/battery observers
        │   ├── PowerLockService.java     # Accessibility service: power-menu detection
        │   ├── AirplaneModeReceiver.java # Boot + airplane-mode broadcast receiver
        │   ├── AdminReceiver.java        # Device Admin receiver (uninstall protection)
        │   └── AccessLog.java            # Tamper / activity log (new)
        └── res/
            ├── layout/                   # activity_main, activity_password
            ├── values/                   # strings, styles
            ├── xml/                      # device_admin, accessibility_service
            └── drawable/                 # ic_launcher

Permissions

Permission	Why it is needed
RECEIVE_BOOT_COMPLETED	Restart the monitor service after reboot
FOREGROUND_SERVICE / FOREGROUND_SERVICE_SPECIAL_USE	Keep monitoring running
SYSTEM_ALERT_WINDOW	Show the lock screen over other apps
BIND_DEVICE_ADMIN	Uninstall protection
READ_PHONE_STATE	Mobile-data state checks
WRITE_SECURE_SETTINGS	Toggle battery saver (granted once via ADB)

Disclaimer

This app is intended for legitimate parental control of devices you own or are authorized to manage. Use it responsibly and in accordance with applicable laws.

License

No license file is currently included. All rights reserved by the repository owner unless a license is added.