Cirno
by YuSaki丶Kanade · GPL-3.0-only · open source
An app freezer for rooted phones: apps left in the background are frozen so they use no CPU. It has no interface and works automatically once enabled.
Needs:Root + LSPosed · Android 12+ · kernel 5.0+
2113 Apps is independent, not affiliated with or endorsed by YuSaki丶Kanade. Official sources: source code on GitHub.
- Version
- 7.0
- Size
- 20.4 MB
- Requires
- Android 12+
- Updated
- 2025-06-16
Introduction
Android already limits what background apps can do, but many apps still wake up and use the processor while you aren’t looking at them. Cirno freezes them. In the developer’s words, it makes background apps use no CPU resources at all, with the goal of making the whole phone run more smoothly.
What it needs
This is not an app for an unmodified phone. All three conditions have to be met:
- Root and an Xposed framework. Cirno is an Xposed module: its APK contains the Xposed entry file (
assets/xposed_init), and it also bundles libsu, a library for running root shell commands. You need root plus LSPosed or its successor. See how to install LSPosed. - Android 12 or later. The APK won’t install on older versions.
- A kernel with cgroup v2, which the developer says means Linux kernel 5.0 or newer. Devices without cgroup v2 aren’t supported. Your kernel version is usually shown under About phone in Settings.
How it behaves
- There is no interface. Cirno has no screen to configure. Once it’s enabled as a module and you reboot, it freezes background apps automatically.
- Exceptions go in a config file. To keep a particular app from being frozen, the developer says to edit Cirno’s cfg file. Neither the short README nor the store description says where the file is or how it’s written, so check the project’s GitHub before you rely on exceptions.
Freezing is powerful, and it isn’t right for every app. Anything that has to work in the background, such as music playback, navigation, messaging you want notifications from, or an alarm, may stop working while frozen. Those are the apps to add as exceptions. Test after enabling it, and remember that disabling the module and rebooting undoes everything.
About the name
The README says the name comes from Cirno, a character from the Touhou Project games, who is an ice fairy.
What’s inside the APK
Trackers
No code matching the Exodus Privacy tracker signatures.
Native code
Runs on 64-bit and older 32-bit ARM phones.
Android versions
Built for Android 15 (target API 35).
Permissions
0 of them need your approval first.
Xposed API. Built against the Xposed API. It needs an Xposed framework such as LSPosed, which in turn needs root. (de.robv.android.xposed.IXposedHookLoadPackage)
libsu (root shell). Bundles libsu, a library for running commands in a root shell. (com.topjohnwu.superuser.CallbackList$$ExternalSyntheticLambda0)
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).
Granted at install (1)
Low-risk permissions Android grants automatically, plus any we have not classified.
- QUERY_ALL_PACKAGES
Defined by other apps (1)
Permissions that belong to another app or to this app itself.
- nep.timeline.cirno.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
More Information
- Package name
- nep.timeline.cirno
- Version
- 7.0 (build 7)
- File size
- 20.4 MB (20,448,736 bytes)
- Requires
- Android 12 or later
- Category
- Root & Mods
- License
- GPL-3.0-only
- Developer
- YuSaki丶Kanade
- Source code
- github.com/Freezer-Team/Cirno
- Released
- Jun 16, 2025
- Signer SHA-256
- cc437a8c20884735fce878e1ce02014cf69e7b360eec5f13f438e516973d2fa6
- File SHA-256
- 8289b90780ab9c5a54df5c8644a770842f60833164e58ad595de504230ebcf26
- Checked
- , against the IzzyOnDroid index · how we check · verify it yourself
Common questions
Is this APK the official Cirno release?
Yes. It is the developer’s own release of Cirno 7.0, byte for byte as IzzyOnDroid distributes it. Its SHA-256 matches IzzyOnDroid’s signed index, and it is signed with the certificate IzzyOnDroid records for the app (SHA-256 cc437a8c20884735fce878e1ce02014cf69e7b360eec5f13f438e516973d2fa6).
What Android version does Cirno need?
Android 12 or later (API level 31). Version 7.0 is built for Android 15 (target API 35). Runs on 64-bit and older 32-bit ARM phones.
Can Cirno access the internet?
No. The APK doesn’t request Android’s internet permission, so the app can’t go online by itself. In total it declares 2 permissions, and none of them needs your approval first.
Does Cirno contain trackers?
No known trackers: our scan of version 7.0 found no code matching the Exodus Privacy tracker signatures. The scan covers known tracker libraries; it doesn’t show what data the app itself sends.
Is Cirno open source?
Yes. Cirno is released under the GPL-3.0-only licence, and its source code is published at https://github.com/Freezer-Team/Cirno.
Recent releases
| Version | Released | Size | Requires |
|---|---|---|---|
| v7.0 · this download | Jun 16, 2025 | 20.4 MB | Android 12+ |
| v6.0 | Jun 15, 2025 | 20.4 MB | Android 12+ |
Versions currently kept in the IzzyOnDroid repository. We host and check only the newest one. Full changelog.
