Hail

Hail is an open-source app freezer by 艾星 Aistra. To freeze an app here means to switch it off without uninstalling it, until you unfreeze it; the project says this helps cut memory use and save battery. The app and its data stay on the phone.

Three ways to freeze

• Disable: the app disappears from the launcher and shows as Disabled in the app list.
• Hide: the app disappears from the app list too. The README calls this “almost like an uninstalled state”: the app and its data stay, but it is unavailable.
• Suspend (Android 7.0+): the icon turns grey, notifications are hidden, and opening the app only shows a message that it is suspended. The README stresses that this does not stop the app running in the background.

Working modes

Hail needs elevated rights, and which freeze methods you get depends on how you give them:

• Shizuku is the one the developer recommends. Without root it runs over wireless debugging on Android 11 and later; see how to start Shizuku.
• Root works too, but the README warns that it is slower.
• Device owner is set once from a computer with adb shell dpm set-device-owner com.aistra.hail/.receiver.DeviceAdminReceiver. You then have to remove it in Hail’s settings before you can uninstall Hail.
• Use the same mode to unfreeze. In the README’s words, “any app that has been frozen on Hail will need to be unfrozen by the same working mode.”

Automation

Automation apps can freeze, unfreeze and launch apps through Hail, by intent or with hail:// links. Hail can also freeze apps automatically, freeze or unfreeze everything under a tag, and keep a whitelist. An optional Xposed module lets apps you pick, its “scoped apps”, open apps that Hail has suspended.

If something goes wrong

Freezing the wrong system app can break things. The README’s ways back, without Hail:

adb shell pm enable com.package.name
adb shell su -c pm unhide com.package.name
adb shell pm unsuspend com.package.name

The middle one, for hidden apps, needs root. Its last resort is wiping the phone from recovery, which the developer calls “none of my business”.

About this file

• This is F-Droid’s build, signed with F-Droid’s key (SHA-256 fingerprint starting E3:E3:C4:92). The releases on GitHub are signed by the developer, so the two can’t update each other; see package conflicts.
• It doesn’t request internet access, and our scan found no tracker libraries. Hail isn’t on Google Play.
• The 5.8 MB file runs on Android 6.0 and later, on ARM and x86, 32- and 64-bit, and declares 20 permissions, 1 of which needs your approval. The powerful ones, such as force-stopping and disabling apps, come through the working mode you choose.
• Hail is licensed under GPL-3.0 or later.

Shizuku API. Uses the Shizuku API, so it can do ADB-level work without root once Shizuku is running. (rikka.shizuku.ShizukuProvider)

Xposed API. Built against the Xposed API. It needs an Xposed framework such as LSPosed, which in turn needs root. (io.github.libxposed.api.XposedInterface$Chain)

CPU types in this build: arm64-v8a (64-bit ARM, almost every phone since 2017); armeabi-v7a (32-bit ARM, older and budget phones); x86 (32-bit Intel, emulators); x86_64 (64-bit Intel, emulators and Chromebooks).

Versions currently kept in the F-Droid repository. We host and check only the newest one. Full changelog.