A minimalist Android app that blocks distracting apps using NFC tags and scheduled modes. Built to add physical friction between you and your phone.
Google Play · Releases · Website
Concept
nfcGuard forces you to physically interact with an NFC tag to unlock blocked apps. Place your tag somewhere inconvenient — your kitchen, gym bag, a friend's house — and you'll think twice before mindlessly opening Instagram.
Flow: Create a mode → select apps to block (or allow) → optionally link NFC tags → optionally set a schedule → activate → stay focused → tap your NFC tag when you actually need access.
If no NFC tag is linked to a mode, any NFC-capable object (smartwatch, headphones, transit card) can deactivate it.
Screenshots
Main Screens
Overlay in Action
Features
Modes
Two blocking strategies:
- Block Selected — block specific distracting apps while everything else remains accessible
- Allow Only — block everything except a whitelist of essential apps
Each mode can have multiple NFC tags linked to it. Each tag can be individually configured:
- Permanent unlock — tapping the tag fully deactivates the mode until the next scheduled activation
- Temporary unlock — tapping the tag unlocks for a configurable duration (e.g. 5 minutes), after which the mode automatically reactivates
This lets you set up different levels of access. For example, keep one tag at home for full unlock and another at work that only gives you 5 minutes — enough to quickly check something without falling down a scroll hole.
Schedules
Automate mode activation with flexible scheduling:
- Per-day time configuration (different start/end times for each day of the week)
- Optional automatic deactivation at end time
- Multiple modes can be linked to a single schedule
- Visual status badges: ACTIVE when a schedule is running, DEACTIVATED when dismissed early via NFC
NFC Integration
- Register physical NFC tags by tapping them to your device
- Link multiple tags to a single mode, each with its own unlock behavior
- Configure per-tag unlock duration (permanent or temporary with a time limit)
- Modes with linked tags require one of those specific tags — other tags won't work
- Wrong-tag feedback when an incorrect tag is scanned
Settings & Permissions
Accessible via the gear icon on the home screen:
- Permission status — see which permissions are granted, tap to open the relevant system settings
- Export/Import — back up your entire configuration (modes, schedules, NFC tags) in JSON or YAML format
- Export to share configs between devices or keep a backup
- Import with two strategies: Replace (overwrite everything) or Merge (add non-duplicate items)
- Pause App reminder — quick link to disable Android's "Pause app if unused" setting
Emergency Reset
If you lose your NFC tag:
- Tap the delete icon on the home screen
- Complete the safety flow (90-second cooldown + confirmation text)
- Select which tags you lost
- All modes are deactivated and selected tags are removed — your configurations stay intact
Technical Details
Requirements
- Android 8.0+ (API 26)
- NFC hardware (for NFC unlock features)
- Permissions:
- Usage Access — detect which app is in the foreground
- Display Over Apps — show the block overlay
- Battery Optimization exemption — ensure reliable background operation
- Disable "Pause app if unused" — prevent Android from hibernating nfcGuard
Architecture
- Kotlin with Jetpack Compose for a fully declarative UI
- Foreground Service pattern for persistent app blocking across reboots and task kills
- AlarmManager with exact alarms for precise schedule execution
- SharedPreferences for lightweight state persistence
- kotlinx.serialization for JSON state management and config export
- BroadcastReceivers for boot, package update, and alarm events
How Blocking Works
nfcGuard runs a foreground service that polls the current foreground app via UsageStatsManager, with an AccessibilityService fallback for devices where UsageStatsManager misreports on recent-apps transitions (Pixel, some Samsung). When a blocked app is detected, a full-screen overlay is displayed, preventing interaction until the user switches away or unlocks with an NFC tag.
Installation
Google Play: Download from Play Store
APK: Go to the Releases page and download the latest APK. Install it on your device, grant the necessary permissions, and configure your modes and schedules.
Manual Installation
- Clone the repository
- Open in Android Studio
- Build and run on a physical device (emulator NFC support is limited)
Configuration for Custom ROMs
Some manufacturers (Xiaomi, Samsung, Huawei) aggressively kill background services. After installation:
- Settings → Apps → nfcGuard — disable "Pause app activity if unused"
- Enable Autostart if available (MIUI, ColorOS)
- Set battery optimization to Unrestricted / No restrictions
- On MIUI: add nfcGuard to the Lock screen cleanup whitelist
Export Format Examples
JSON
{
"version": 1,
"modes": [
{
"id": "abc-123",
"name": "Work Focus",
"blockedApps": ["com.instagram.android", "com.twitter.android"],
"blockMode": "BLOCK_SELECTED",
"nfcTagIds": ["tag-001", "tag-002"]
}
],
"schedules": [],
"nfcTags": [
{
"id": "tag-001",
"name": "Home tag",
"unlockDurationMinutes": null
},
{
"id": "tag-002",
"name": "Work tag",
"unlockDurationMinutes": 5
}
]
}YAML
# nfcGuard Configuration Export version: 1 modes: - id: "abc-123" name: "Work Focus" blockMode: BLOCK_SELECTED nfcTagIds: - "tag-001" - "tag-002" blockedApps: - "com.instagram.android" - "com.twitter.android" schedules: [] nfcTags: - id: "tag-001" name: "Home tag" unlockDurationMinutes: null # permanent unlock - id: "tag-002" name: "Work tag" unlockDurationMinutes: 5 # temporary 5-minute unlock
My personal configuration
Click to view my personal configuration
{ "version": 1, "modes": [ { "id": "2fc26ed7-25a2-4696-9d57-c6f0fec210cd", "name": "Daily", "blockedApps": [ "co.hinge.app", "com.reddit.frontpage", "com.spotify.music", "com.zhiliaoapp.musically", "com.google.android.apps.youtube.music", "app.revanced.android.apps.youtube.music", "com.yandex.browser", "app.revanced.android.youtube", "com.instagram.android", ], "blockMode": "BLOCK_SELECTED", "nfcTagId": "0463b1f1220289", }, { "id": "e3a2e7c8-55eb-4d59-8cbf-2ada6dc0ff05", "name": "evening", "blockedApps": [ "co.hinge.app", "app.revanced.android.youtube", "com.yandex.browser", ], "blockMode": "BLOCK_SELECTED", "nfcTagId": "0463b1f1220289", }, ], "schedules": [ { "id": "fd1c04cb-b43e-4f43-961a-313fb5db773f", "name": "morning", "timeSlot": { "dayTimes": [ { "day": 1, "startHour": 0, "startMinute": 0, "endHour": 11, "endMinute": 59, }, { "day": 2, "startHour": 0, "startMinute": 0, "endHour": 11, "endMinute": 59, }, { "day": 3, "startHour": 0, "startMinute": 0, "endHour": 11, "endMinute": 59, }, { "day": 4, "startHour": 0, "startMinute": 0, "endHour": 11, "endMinute": 59, }, { "day": 5, "startHour": 0, "startMinute": 0, "endHour": 11, "endMinute": 59, }, { "day": 6, "startHour": 0, "startMinute": 0, "endHour": 11, "endMinute": 59, }, { "day": 7, "startHour": 0, "startMinute": 0, "endHour": 11, "endMinute": 59, }, ], }, "linkedModeIds": ["2fc26ed7-25a2-4696-9d57-c6f0fec210cd"], "hasEndTime": true, }, { "id": "2e4c179e-bbff-4ba6-8634-3980187f9788", "name": "day ", "timeSlot": { "dayTimes": [ { "day": 1, "startHour": 12, "startMinute": 15, "endHour": 14, "endMinute": 59, }, { "day": 2, "startHour": 12, "startMinute": 15, "endHour": 14, "endMinute": 59, }, { "day": 3, "startHour": 12, "startMinute": 15, "endHour": 14, "endMinute": 59, }, { "day": 4, "startHour": 12, "startMinute": 15, "endHour": 14, "endMinute": 59, }, { "day": 5, "startHour": 12, "startMinute": 15, "endHour": 14, "endMinute": 59, }, { "day": 6, "startHour": 12, "startMinute": 15, "endHour": 14, "endMinute": 59, }, { "day": 7, "startHour": 12, "startMinute": 15, "endHour": 14, "endMinute": 59, }, ], }, "linkedModeIds": ["2fc26ed7-25a2-4696-9d57-c6f0fec210cd"], "hasEndTime": true, }, { "id": "9b0ff839-eaba-4aa5-a55f-a1873deb6a26", "name": "late day", "timeSlot": { "dayTimes": [ { "day": 1, "startHour": 15, "startMinute": 15, "endHour": 17, "endMinute": 59, }, { "day": 2, "startHour": 15, "startMinute": 15, "endHour": 17, "endMinute": 59, }, { "day": 3, "startHour": 15, "startMinute": 15, "endHour": 17, "endMinute": 59, }, { "day": 4, "startHour": 15, "startMinute": 15, "endHour": 17, "endMinute": 59, }, { "day": 5, "startHour": 15, "startMinute": 15, "endHour": 17, "endMinute": 59, }, { "day": 6, "startHour": 15, "startMinute": 15, "endHour": 17, "endMinute": 59, }, { "day": 7, "startHour": 15, "startMinute": 15, "endHour": 17, "endMinute": 59, }, ], }, "linkedModeIds": ["2fc26ed7-25a2-4696-9d57-c6f0fec210cd"], "hasEndTime": true, }, { "id": "ec2a3b62-8056-404e-9f2c-c5aed210a163", "name": "evening", "timeSlot": { "dayTimes": [ { "day": 1, "startHour": 18, "startMinute": 15, "endHour": 20, "endMinute": 59, }, { "day": 2, "startHour": 18, "startMinute": 15, "endHour": 20, "endMinute": 59, }, { "day": 3, "startHour": 18, "startMinute": 15, "endHour": 20, "endMinute": 59, }, { "day": 4, "startHour": 18, "startMinute": 15, "endHour": 20, "endMinute": 59, }, { "day": 5, "startHour": 18, "startMinute": 15, "endHour": 20, "endMinute": 59, }, { "day": 6, "startHour": 18, "startMinute": 15, "endHour": 20, "endMinute": 59, }, { "day": 7, "startHour": 18, "startMinute": 15, "endHour": 20, "endMinute": 59, }, ], }, "linkedModeIds": ["e3a2e7c8-55eb-4d59-8cbf-2ada6dc0ff05"], "hasEndTime": true, }, { "id": "b7bf3650-a6c9-4cbd-92ca-f9dd77128099", "name": "night", "timeSlot": { "dayTimes": [ { "day": 1, "startHour": 21, "startMinute": 15, "endHour": 23, "endMinute": 59, }, { "day": 2, "startHour": 21, "startMinute": 15, "endHour": 23, "endMinute": 59, }, { "day": 3, "startHour": 21, "startMinute": 15, "endHour": 23, "endMinute": 59, }, { "day": 4, "startHour": 21, "startMinute": 15, "endHour": 23, "endMinute": 59, }, { "day": 5, "startHour": 21, "startMinute": 15, "endHour": 23, "endMinute": 59, }, { "day": 6, "startHour": 21, "startMinute": 15, "endHour": 23, "endMinute": 59, }, { "day": 7, "startHour": 21, "startMinute": 15, "endHour": 23, "endMinute": 59, }, ], }, "linkedModeIds": ["e3a2e7c8-55eb-4d59-8cbf-2ada6dc0ff05"], "hasEndTime": false, }, ], "nfcTags": [{ "id": "0463b1f1220289", "name": "NFC card", "linkedModeIds": [] }], }
License
MIT License
Contributing
Contributions are welcome. Open an issue or submit a pull request.
Acknowledgments
Claude AI was used during the development of this project for writing code and UI design.