FocusLock

Android app/website blocker with a fixed usage cycle.

How it works

15 minutes of use → 2 hours locked → 15 minutes → …

Every monitored app and every monitored website follows the same cycle. When the counter hits 15 min, a full-screen lock activity opens over the target and you get bounced to the home screen until the 2 h are up. Solving the emergency puzzle resets the cycle early.

Features

• App blocking via UsageStatsManager.
• Website blocking in Chrome, Firefox, Samsung Internet, Edge, Brave, Opera, DuckDuckGo and Vivaldi — an AccessibilityService reads the URL bar so the same cycle applies to e.g. twitter.com.
• Shared-timer groups: multiple entries (Insta app + instagram.com + twitter.com) can share one 15/2 h budget. Group membership is frozen while a block is active.
• Emergency unlock: 60-character random-string transcription puzzle. FLAG_SECURE blocks Circle to Search and screenshots, paste menu disabled, keyboard suggestions off, bulk-input rejected.
• 12-of-15 min warning toast.
• Stats: streak counter, daily totals, 7-day chart, per-app breakdown, 60 days of history.

Implementation notes

• Foreground service polls every second, ticks usedMs on the matching AppState or shared MonitorGroup.
• Browser host detection runs in an in-memory StateFlow — nothing about your browsing is persisted or sent anywhere.
• SystemClock.elapsedRealtime() for delta math, immune to wall-clock jumps (NTP, DST, midnight rollover).
• Service self-restarts via onTaskRemoved + a 10-minute inexact AlarmManager watchdog to survive Doze and Samsung's background-kill behavior.
• Persistence via androidx.datastore (JSON). No network calls, no telemetry.

Source under app/src/main/java/com/personal/focuslock/.

Build

./gradlew :app:assembleDebug

Requires JDK 17 and Android SDK with compileSdk 35.

License

MIT — see LICENSE.