Fern

wized2

1.8.4 · GitHub

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Miscellaneous Android 8.0+ 2 days ago Proprietary

40 ShizuStore

53 GitHub

5 Stars

1 MB Size

More about this app

Material 3 live system monitor for CPU, RAM, storage, battery, thermal and network, with an optional Shizuku shell for elevated readings.

Fern

Live system pulse for Android — CPU, RAM, storage, battery, thermal, network, and hardware tests.

Material 3 · offline · no ads · small release APK (R8 + resource shrink).

Features

Metric	Source
CPU %	Multi-path `/proc/stat` dual-sample + cross-tick; loadavg fallback
CPU detail	Cores, current/max MHz, governor, ABI, chip, load 1/5/15
RAM	Used / free / total + app heap
Storage	Internal `StatFs`; external when distinct
Battery	Level, charge state, health, tech, °C, mV, mA + sparkline
Thermal	`PowerManager` status (API 29+)
Network	Type + live KB/s throughput
Display	Resolution, DPI, refresh Hz
System	Security patch, kernel, locale, timezone, sensor count

Tabs

Home — live status, gauges, bars, trend sparklines, manual refresh
Details — processor, memory, power, display, device peaks; share snapshot
Active Apps — recently active apps (optional Usage access; data stays on device)
More — Tests, Settings, Sensors

Permissions

Permission	Required	Purpose
`ACCESS_NETWORK_STATE`	yes	Network type / throughput on Home
`VIBRATE`	yes	Haptics and Tests vibration
`PACKAGE_USAGE_STATS`	optional	Active Apps only — user grants Usage access in system settings; never leaves the device

No internet permission. No accounts. No tracking.

Advanced mode (optional)

Off by default. In More → Settings, enable Advanced mode to use Shizuku (recommended) or root:

Real thermal zones for the Home Thermal bar
Per-app memory on Active Apps
Force-stop from the app list

Shizuku never runs until you install it, start it, and grant Fern. Root is only used if su is present and Advanced mode is on.

UX

Centered top bar, fade tab transitions, nav labels only when selected
Soft surface containers, refined green Material 3 palette (light + OLED dark)
Sampling can pause in background; optional haptic feedback

Fully offline after install.

Build

./gradlew assembleDebug assembleRelease

Min SDK 26 · Target 35 · Kotlin + Jetpack Compose + Material 3.

CI builds debug + release APKs and attaches them to GitHub Releases on main / tags.
Release signing uses GitHub secrets when present; otherwise falls back to the debug keystore.

Changelog

See CHANGELOG.md.

Website

Landing page: index.html at the repo root (GitHub Pages from /). Not part of the Android APK build.

License

MIT · wized2/Fern

How Shizuku is used

Can read accurate CPU, per-app memory and CPU, thermal sensors and force-stop apps via `Shizuku` shell and system service

This is an AI-assisted analysis of Shizuku-related usages in the app's public source code. It is best effort, so it may not catch every single usage.

How this app uses Shizuku

Fern uses Shizuku to power an optional Advanced mode with more accurate system readings and app control.

Measure accurate CPU: reads total CPU load from cat /proc/stat twice through Shizuku to calculate real usage for the monitor.
Show per-app memory: collects per package memory use with the dumpsys meminfo shell command through Shizuku, falling back to the ps shell command.
Show per-app CPU: collects top package CPU use with the dumpsys cpuinfo shell command through Shizuku for the Active Apps list.
Read thermal sensors: reads temperature zones from the thermal sysfs through Shizuku to show zone list and maximum temperature.
Stop running apps: stops an app selected in the Active Apps list with the Activity Manager force stop function through Shizuku, or with the am force-stop shell command through Shizuku.

Android APIs or commands used

cat /proc/stat
dumpsys meminfo
dumpsys cpuinfo
ps -A -o NAME,RSS
cat /sys/class/thermal/thermal_zone*/type
cat /sys/class/thermal/thermal_zone*/temp
am force-stop
android.app.IActivityManager#forceStopPackage

Changelog

What's new for version 1.8.4

Fern 1.8.4

Live system pulse — Material 3 resource monitor.

Fern-release.apk — R8 + resource-shrunk (from main)

What's new

Advanced mode (optional): Shizuku or root for thermal zones, per-app RAM/CPU, force-stop
Active Apps, Sensors, Hardware details, thermal bar on Home
OLED-friendly dark theme · offline · no ads

Important (Shizuku): start Shizuku → allow package com.endroid.fern → open Fern → Advanced ON → Grant / Refresh.

Debug APK is a workflow artifact on this run.

Min SDK 26 · MIT

Full Changelog: https://github.com/wized2/Fern/compare/v1.8.3...v1.8.4