Blink

character-flat

1.1.0 · GitHub

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Productivity Android 14+ 4 months ago GPL-3.0

29 ShizuStore

688 GitHub

23 Stars

1 MB Size

More about this app

A persistent, highly customizable 20-20-20 rule eye-care timer that uses Shizuku to whitelist itself from Android's battery optimizations

Blink

A bulletproof 20-20-20 rule timer for Android that actually works.

Blink is a persistent eye-care daemon that reminds you to rest your eyes every 20 minutes. Unlike other timer apps, it uses exact alarms and a foreground service to survive Android's aggressive battery optimizations — your timer fires on time, every time, even during Doze mode.

When it's time, a beautiful fullscreen overlay appears on top of whatever you're doing (no app switching, no interruptions) and counts down 20 seconds for you to look at something 20 feet away.

✨ Features

Core

Feature	Description
Exact Alarms	Uses `AlarmManager.setExactAndAllowWhileIdle` — fires during deep sleep & Doze
Foreground Service	Persistent `specialUse` FGS with live countdown notification
True Overlay	`TYPE_APPLICATION_OVERLAY` floats on top of all apps without replacing them
Smart Screen Detection	Pauses on screen off, resets after >20s lock, resumes on short locks
Boot Receiver	Optional auto-start when device reboots

Customization

Feature	Description
3 Overlay Styles	Expressive (animated rings, ripple waves, orbital dots), Calm (smooth arc, gentle glow), Minimal (clean progress circle)
Dynamic M3 Theming	Colors pulled from your wallpaper via `dynamicColorScheme()`
Alert Modes	Choose between: Overlay only, Notification only, or Both
Adjustable Timers	Work: 1–60 min, Rest: 10–60 sec
Overlay Opacity	30–100% transparency
Dismissable Mode	Optional close button (red FAB) during rest overlay
Landscape Support	Responsive layout adapts to orientation

Battery & Reliability

Feature	Description
Shizuku Integration	Optional — auto-whitelists app from battery optimization via `cmd deviceidle whitelist`
Battery Optimization	Built-in toggle to request unrestricted battery access
START_STICKY	Service restarts itself if killed by the OS
Watchdog Alarm	5-minute exact alarm verifies service liveness, restarts if dead
Direct Boot	Starts on `LOCKED_BOOT_COMPLETED` before device unlock
OEM Guides	Per-manufacturer battery settings instructions (Xiaomi, Samsung, OPPO, Vivo, etc.)

📦 Download

→ Latest Release

Build	Size	Description
`blink-v1.1.0-release.apk`	~1.8 MB	Signed, R8-minified release build
`blink-v1.1.0-debug.apk`	~10 MB	Debug build with logging

See CHANGELOG.md for release notes.

Requirements

Android 14+ (API 34)
Display over other apps permission (for the overlay)
Notification permission
Exact alarm permission

🏗️ Architecture

┌─────────────────────────────────────────────────┐
│  MainActivity (Jetpack Compose / M3)            │
│  ├── Timer Ring (segmented arc, 60fps)          │
│  ├── Start/Stop FAB                             │
│  └── Settings FAB → SettingsScreen              │
├─────────────────────────────────────────────────┤
│  EyeCareService (Foreground Service)            │
│  ├── AlarmManager (exact, idle-safe)            │
│  ├── BroadcastReceiver (SCREEN_ON/OFF)          │
│  ├── Countdown coroutine (1s tick)              │
│  └── Persistent notification (live countdown)   │
├─────────────────────────────────────────────────┤
│  RestOverlayService (TYPE_APPLICATION_OVERLAY)  │
│  ├── ComposeView in WindowManager               │
│  ├── 3 style composables (Expressive/Calm/Min) │
│  ├── 60fps raw progress (no animateFloatAsState)│
│  └── Vibration at start + end                   │
├─────────────────────────────────────────────────┤
│  ShizukuUtils → cmd deviceidle whitelist        │
│  BootReceiver → auto-start on reboot            │
│  AlarmReceiver → wakes EyeCareService           │
│  PrefsManager → SharedPreferences wrapper       │
└─────────────────────────────────────────────────┘

Key Design Decisions

No WorkManager — too imprecise for 20-minute intervals. AlarmManager.setExactAndAllowWhileIdle is the only reliable option.
True overlay, not Activity — TYPE_APPLICATION_OVERLAY stays on top without replacing the current app. Activities would force-switch context.
ComposeView in Service — requires setting all three tree owners (LifecycleOwner, SavedStateRegistryOwner, ViewModelStoreOwner) manually.
Raw 16ms countdown — animateFloatAsState on an already-updating mutableState causes jitter. Direct delay(16) loop gives smooth ~60fps arc animation.
R8 on debug builds — material-icons-extended is ~30MB unshrinked. R8 tree-shakes unused icons down to <2MB.

🔨 Build

# Debug
./gradlew assembleDebug

# Release (requires signing key)
./gradlew assembleRelease

Tech Stack

Language: Kotlin 2.1
UI: Jetpack Compose + Material 3 (Dynamic Color)
Min SDK: 34 (Android 14)
Build: Gradle 8.9, AGP 8.7.3, Compose BOM 2024.12.01
Dependencies: Shizuku 13.1.5, Coroutines 1.8.1

📄 License

GNU General Public License v3.

How Shizuku is used

Can whitelist itself from battery optimization via `cmd deviceidle whitelist` through Shizuku.

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

Blink uses Shizuku to keep its eye care timers reliable in the background.

Exempt from battery optimization: adds itself to the system idle whitelist with the cmd deviceidle whitelist shell command through Shizuku so reminders continue on schedule, and checks whether it is already whitelisted the same way.

Android APIs or commands used

cmd deviceidle whitelist

Notable details

Battery exemption can also be requested through the standard system prompt without Shizuku.

Changelog

What's new for version 1.1.0

v1.1.0

Reliability Improvements Service calls startForeground() in onCreate() — closes the empty-process kill window Timer state persisted across OS-initiated restarts (no longer cleared in onDestroy) Watchdog alarm fires every 5 minutes via setExactAndAllowWhileIdle to auto-restart dead service Direct boot support (LOCKED_BOOT_COMPLETED) — service starts before device unlock AlarmReceiver independently restarts service if found dead

UX Improvements OEM-specific battery settings guide (Xiaomi, Samsung, OPPO/Realme/OnePlus, Vivo, Motorola, Huawei, ASUS, Nokia) Each OEM guide includes auto-start whitelist steps and force-stop warning Shizuku is now fully optional — app works without it (only used for one-tap battery whitelist)

Housekeeping Package renamed from com.eyecare.daemon to com.cflat.blink License: GNU General Public License v3