App Privacy Guard

A Flutter plugin to protect sensitive information when your app goes into the background or is displayed in the iOS App Switcher.

This plugin provides:

Blur Mode (iOS & Android) – Adds a system blur layer over your app window when it is backgrounded.
Secure Mode (Android only) – Prevents screenshots and screen recording.
Dynamic Island Watermark (iOS only) – Displays a small watermark logo centered below the Dynamic Island, always above blur overlays.

Features

🚫 Hide sensitive data in the app switcher with a blur overlay.
🔒 Prevent screenshots & screen recordings on Android.
🌊 Always-visible watermark on iOS (e.g., your app logo below Dynamic Island).
⚡ Simple Dart API with manual and automatic lifecycle integration.

Installation

Add to your pubspec.yaml:

dependencies:
  app_privacy_guard:
    git:
      url: https://github.com/your-org/app_privacy_guard.git

Run:

flutter pub get

Usage

Import

import 'package:app_privacy_guard/app_privacy_guard.dart';

Manual Blur/Secure Control

// Enable blur overlay
await AppPrivacyGuard.instance.enableBlur();

// Disable blur overlay
await AppPrivacyGuard.instance.disableBlur();

// Enable secure mode (Android only)
await AppPrivacyGuard.instance.enableSecure();

// Disable secure mode
await AppPrivacyGuard.instance.disableSecure();

Auto Mode (Lifecycle-aware)

@override
void initState() {
  super.initState();
  // Automatically enable blur when app goes to background
  AppPrivacyGuard.instance.startAuto(mode: PrivacyMode.blur);
}

@override
void dispose() {
  AppPrivacyGuard.instance.stopAuto();
  super.dispose();
}

Dynamic Island Watermark (iOS only)

// Show watermark
await AppPrivacyGuard.instance.showWatermark(
  assetName: 'watermark_icon', // iOS Assets.xcassets
  size: 22,
  offsetY: 6,
  alpha: 0.9,
);

// Update watermark position or size
await AppPrivacyGuard.instance.updateWatermark(size: 20, offsetY: 8, alpha: 0.85);

// Hide watermark
await AppPrivacyGuard.instance.hideWatermark();

Tip: Add your watermark icon to ios/Runner/Assets.xcassets.

iOS Notes

Blur is implemented using UIVisualEffectView.
Watermark is shown in a separate UIWindow with high windowLevel, so it stays visible above blur overlays.
Secure mode calls are no-op on iOS (screenshots cannot be blocked globally).

Android Notes

Blur is implemented using a simple overlay view.
Secure mode sets FLAG_SECURE on the activity window.

Example

See the /example folder for a complete usage sample.