Aminul MultiBook

Created by Aminulsordar
Multiple Accounts, One App

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1. Project Overview

Aminul MultiBook is a lightweight, production-grade Android application inspired by Facebook Lite that allows users to add and manage multiple Facebook accounts simultaneously within a single native Android client.

The application achieves true browser session isolation by leveraging the AndroidX WebKit Multi-Profile Architecture (ProfileStore & WebViewCompat.setProfile), ensuring each saved Facebook account maintains its own completely independent:

• Authentication cookies (profile.cookieManager)
• Web Storage, LocalStorage & IndexedDB (profile.webStorage)
• Session cookies & HTTP authentication state
• Browser cache & offline storage
• Independent login and logout flows (logging out of Account A does NOT affect Account B)

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2. Technology Stack & Identity

• Developer: Aminulsordar
• Application Name: Aminul MultiBook
• Package: com.aminul.multibook
• Target Platform: Android 8.0 (API level 26) through Android 15+ (API level 36)
• UI Architecture: Jetpack Compose with Material Design 3 (M3)
• Custom Branding: Professional adaptive multi-card browser icon in electric blue, white, and dark navy
• Splash Screen: Animated branded splash screen with "Created by Aminulsordar" signature badge
• Extensions: Integrated c3c-fbstate extension suite for exporting and importing Facebook session states (fbstate.json), with AES-256 CTR encryption/decryption and safe logout support.
• Desktop Mode: Full PC user-agent switching, wide responsive viewport, zoom controls, and immersive fullscreen browsing
• Session Isolation: AndroidX WebKit ProfileStore and per-account Profile Management
• Local Database: Android Jetpack Room Database with Kotlin Coroutines and KSP

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3. c3c-fbstate Extension Integration

The application natively integrates the c3c-fbstate extension functionality:

• Export FBState: Extracts the current account's cookies into standard fbstate.json format for use with bots (C3C, fca-unofficial) or session backup.
• Import FBState: Injects fbstate.json directly into the account's isolated profile and reloads the browser, logging in instantly without typing credentials.
• AES-256 CTR Encryption / Decryption: Full compatibility with c3c-fbstate AES-CTR mode with SHA-256 key derivation, allowing password-protected encrypted exports and imports.
• Safe Logout (not die fbstate): Removes transient session tokens while preserving sb and dbln cookies so Facebook recognizes the profile device.
• Access Points: Directly accessible via the browser toolbar (Extension puzzle icon) and from each Account Card's 3-dot menu on the Home screen.
• Bundled Assets: Source extension assets are bundled in assets/extensions/c3c_fbstate/ inside the APK.

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4. Desktop Mode & Advanced Browsing Features

• Desktop Mode Toggle in Settings: Choose whether accounts open by default in Mobile Mode (m.facebook.com) or Desktop Mode (www.facebook.com).
• Instant In-Browser Switching: Tap the Desktop/Mobile icon directly in the browser toolbar to switch modes on the fly.
• Zero Session Loss: Switching between Mobile and Desktop modes preserves all login cookies and sessions seamlessly because both modes operate on the same isolated account profile.
• PC User-Agent Switching: Emulates modern PC Chrome on Windows 10/11 (Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 ...).
• Zoom Controls: Adjust zoom (+15%, -15%, reset to 100%) directly from the browser toolbar, in addition to native pinch-to-zoom.
• Immersive Fullscreen Mode: Hide system bars and app headers to maximize screen real estate, complete with a floating quick-exit button.

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5. Developer Mode & Diagnostics Dashboard

Enabled via Settings > Developer Mode, unlocking an advanced engineering console:

• App & Android Platform Information: Displays App Name, Developer (Aminulsordar), Package Name, Version 1.0 (Code 1), Android OS Version, Device Model, Manufacturer, Board/Hardware, Supported ABIs, and System Uptime.
• Live RAM & Memory Telemetry: System RAM metrics (Total, Available, Low Memory state) and JVM Heap allocations (Allocated Heap, Free Heap, Max Heap) with manual Garbage Collector trigger.
• WebView Engine Status: Shows installed WebView provider package, version, multi-profile capability, app data directory, and cache directory.
• Interactive Isolation Test Runner: Built-in 4-stage automated test suite that verifies ProfileStore availability, creates isolated test profiles, and verifies cookie segregation boundaries.
• Cache & Storage Reset: On-demand tools to clear HTTP disk cache, wipe WebStorage, and reset global cookie jars.
• Live Diagnostic Logs Viewer: In-memory rolling event logger capturing session transitions, profile loads, and system diagnostics.

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6. Testing Instructions

Test Case 1: c3c-fbstate Extension (Export / Import)

1. Open an account in the browser.
2. Tap the Extension icon (puzzle icon) in the top toolbar.
3. In the Export tab:
   • Tap Plain JSON -> Verify the formatted fbstate.json array appears.
   • Tap Copy to copy to clipboard or Share/Save to share the file.
   • Select Encrypted, enter a password, and verify the encrypted hex string is generated.
4. In the Import tab:
   • Paste an fbstate.json string or tap Select File to pick a .json file.
   • Tap Import & Log In Instantly -> Verify cookies are injected into the isolated profile and the WebView reloads authenticated!
5. Tap Logout (not die fbstate) -> Verify safe logout removes session cookies while keeping device identifiers.

Test Case 2: Desktop Mode & Seamless Switching

1. Tap the Desktop Site icon in the toolbar.
2. Verify the URL switches to www.facebook.com and renders the desktop layout.
3. Verify you remain completely logged in without losing session.

Test Case 3: In-Browser Zoom Controls

1. While browsing, tap the Zoom In menu item.
2. Select Zoom In (+15%); verify the page content magnifies.
3. Select Reset Zoom (100%); verify the page restores to standard 100% scale.

Test Case 4: Developer Mode & Automated Isolation Test Suite

1. Go to Settings > Developer Mode and toggle it ON.
2. Tap Open Developer Dashboard and run Run Isolation Test Suite.
3. Verify all 4 tests pass with green badges.

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7. Building the Application

To build the debug APK from the command line:

gradle :app:assembleDebug

The compiled APK will be generated at: app/build/outputs/apk/debug/app-debug.apk

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8. Author Information

• Developer: Aminulsordar
• Application: Aminul MultiBook
• Package: com.aminul.multibook
• Branding: "Created by Aminulsordar"