Freezer

An Android app freezer that disables apps at the OS level without uninstalling them. Uses Shizuku for privileged access — no root required.

Frozen apps:

• Stop running in the background
• Stop receiving notifications
• Stop draining battery
• Keep all their data — restored instantly on unfreeze

Why

Most app freezers on the Play Store don't actually work. Android's security model only allows OS-level processes (or apps with root, device-owner, or ADB privileges) to disable other apps. Consumer freezer apps fake it with battery restrictions and force-stops that Android reverses within minutes.

Freezer uses Shizuku as a privilege bridge to call Android's real pm disable-user API — the same mechanism the OS itself uses.

Tech stack

• Kotlin + Jetpack Compose
• Shizuku API for privileged operations
• kotlinx.serialization + SharedPreferences for persistence
• Clean architecture: Repository → ViewModel → UI
• Reactive state via StateFlow

Features

• 4×4 grid UI with implicit add tile
• Real OS-level freeze/unfreeze via Shizuku
• Frozen state survives app restart and device reboot
• Syncs UI with OS truth-source on launch (handles external state changes)
• Safety filters block dangerous targets (system apps, Google services, WebView, launchers, authenticators)
• One-time first-launch onboarding
• Smart Shizuku status banner with one-tap restart

Setup

1. Install Shizuku (free, open source — F-Droid or GitHub)
2. Start Shizuku via wireless debugging (one-time per device reboot, ~30 seconds)
3. Install Freezer (APK in Releases)
4. Open Freezer, grant Shizuku permission when prompted
5. Tap +, pick an app, watch it freeze

Known limitations

• Battery savings are not yet measured. Working on it — next phase wires up Android's BatteryStats API.
• App icon position resets after unfreeze. When an app is disabled and re-enabled, your launcher treats it as a fresh install. Stock launchers (Pixel, Samsung) don't preserve original positions; some third-party launchers (Nova, Lawnchair) do.
• Shizuku must be restarted after every device reboot. Inherent to non-rooted Shizuku.
• WhatsApp/messaging app callers see "ringing", not "unreachable". Server-side state, outside any user-space freezer's control.
• Not on Play Store. Google policy restricts apps in this category. Distributed via GitHub Releases.

Building from source

git clone https://github.com/Samantha-fd/freezer.git
cd freezer
# Open in Android Studio (Hedgehog or newer)
# Sync Gradle, build, run

Requires Android Studio Hedgehog+, Android SDK 26+ for runtime, SDK 36 for build.

License

MIT — free to use, modify, distribute. Attribution appreciated.

Built with

This was my first Kotlin/Android project. Paired with Claude (Anthropic) as a learning coach throughout — every line was hand-typed and understood.

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Inspired by missing a feature from an older phone.