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Hail 雹

Hail is a free-as-in-freedom software to freeze Android apps. GitHub Releases

Freeze

Freeze is a word that describes the action of blocking (immediately stopping) apps when they are not needed/in-use ( on-demand request) which in turn helps the device to cut down on the usage of RAM and save power. Users can also unfreeze them to revert to their original state.

In general, "freeze" means disable, but also Hail can "freeze" apps by hiding and suspending them.

Disable

Disabled apps will not be shown in the launcher and will be shown as "Disabled" in the installed apps list. Enable them to revert the action.

Hide

Hidden apps will not be shown in the launcher and in the installed apps list. Unhide them to revert the action.

While in this state, which is almost like an uninstalled state, the package will be unavailable, however, the application data and the actual package file will not be removed from the device.

Suspend (Android 7.0+)

Suspended apps will have their icons shown in grayscale within the device's launcher. Unsuspend them to revert the action.

While in this state, the application's notifications will be hidden, any of its started activities will be stopped and it will not be able to show toasts, dialogs or even play audio. When the user tries to launch a suspended app, the system will, instead, show a dialog to the user informing them that they cannot use this app while it is suspended.

Suspend only prevents the user from interacting with the app, it does NOT prevent the app from running in the background.

Working mode

Any app that has been frozen on Hail will need to be unfrozen by the same working mode.

1. For devices supporting wireless debugging (Android 11+) or rooted devices, Shizuku is recommended.

2. For rooted devices, Root is an alternative. It is slower.

Device Owner

You must remove Hail as a device owner before you can uninstall it

Set device owner by adb

Android Debug Bridge (adb) Guide

Download Android SDK Platform-Tools

Issue adb command:

adb shell dpm set-device-owner com.aistra.hail/.receiver.DeviceAdminReceiver

In response, adb prints this message if device owner has been successfully set:

Success: Device owner set to package com.aistra.hail. Active admin set to component {com.aistra.hail/com.aistra.hail.receiver.DeviceAdminReceiver}

Search the message by search engine otherwise.

Remove device owner

Settings > Remove Device Owner

Privileged System App

The following privapp-permissions is required:

<?xml version="1.0" encoding="utf-8"?>
<permissions>
    <privapp-permissions package="com.aistra.hail">
        <permission name="android.permission.PACKAGE_USAGE_STATS"/>
        <permission name="android.permission.FORCE_STOP_PACKAGES"/>
        <permission name="android.permission.CHANGE_COMPONENT_ENABLED_STATE"/>
        <permission name="android.permission.MANAGE_APP_OPS_MODES"/>
    </privapp-permissions>
</permissions>

To use this mode, you should install Hail as a privileged system app.

The recommended approach is to import Hail when building your ROM, here's an example for Android.bp:

android_app_import {
    name: "Hail",
    apk: "Hail.apk",
    privileged: true,

    dex_preopt: {
        enabled: false,
    },
    presigned: true,
    preprocessed: true,

    required: ["privapp-permissions_com.aistra.hail.xml"]
}

prebuilt_etc {
    name: "privapp-permissions_com.aistra.hail.xml",
    src: "privapp-permissions.xml",
    sub_dir: "permissions",
}

Revert

By adb

Replace com.package.name to the package name of target app.

# Enable app
adb shell pm enable com.package.name
# Unhide app (root required)
adb shell su -c pm unhide com.package.name
# Unsuspend app
adb shell pm unsuspend com.package.name

Modify file

Access /data/system/users/0/package-restrictions.xml, this file stores the restrictions about apps. You can modify, rename or just delete it.

• Enable app: Modify the value of enabled from 2 (DISABLED) or 3 (DISABLED_USER) to 1 (ENABLED)

• Unhide app: Modify the value of hidden from true to false

• Unsuspend app: Modify the value of suspended from true to false

Wipe data by recovery

None of my business :(

API

adb shell am start -a action -e key value

action can be one of the following constants:

• com.aistra.hail.action.LAUNCH: Unfreeze and launch target app. If it is unfrozen, it will launch directly. key="package" value="com.package.name"

• com.aistra.hail.action.FREEZE: Freeze target app. It must be checked at Home. key="package" value="com.package.name"

• com.aistra.hail.action.UNFREEZE: Unfreeze target app. key="package" value="com.package.name"

• com.aistra.hail.action.FREEZE_TAG: Freeze all non-whitelisted apps in the target tag. key="tag" value="Tag name"

• com.aistra.hail.action.UNFREEZE_TAG: Unfreeze all apps in the target tag. key="tag" value="Tag name"

• com.aistra.hail.action.FREEZE_ALL: Freeze all apps at Home. extra is not necessary.

• com.aistra.hail.action.UNFREEZE_ALL: Unfreeze all apps at Home. extra is not necessary.

• com.aistra.hail.action.FREEZE_NON_WHITELISTED: Freeze all non-whitelisted apps at Home. extra is not necessary.

• com.aistra.hail.action.FREEZE_AUTO: Auto freeze apps at Home. extra is not necessary.

• com.aistra.hail.action.LOCK: Lock screen. extra is not necessary.

• com.aistra.hail.action.LOCK_FREEZE: Freeze all apps at Home and lock screen. extra is not necessary.

or use following schema:

• hail://launch?package=xxx

• hail://freeze?package=xxx

• hail://unfreeze?package=xxx

• hail://freeze_tag?tag=xxx

• hail://unfreeze_tag?tag=xxx

• hail://freeze_all

• hail://unfreeze_all

• hail://freeze_non_whitelisted

• hail://freeze_auto

• hail://lock

• hail://lock_freeze

Help Translate

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License

Hail - Freeze Android apps
Copyright (C) 2021-2026 Aistra
Copyright (C) 2022-2026 Hail contributors

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

• 修复 Root 工作模式在低版本 Android 上失效的问题，感谢 @LuoYunXi0407
• 修复 Island/Insular - Hide 模式在部分系统上无法启动应用的问题，感谢 @andy-math
• 修复界面空指针异常，感谢 @lerdb
• 使用 libxposed 并澄清了模块描述

---

• Fix Root modes not working on old Android versions, thanks to @LuoYunXi0407
• Fix Island/Insular - Hide mode can not launch apps in some stock ROM, thanks to @andy-math
• Fix a NullPointerException, thanks to @lerdb
• Use libxposed and clarify the module description