Child Protection Big Sudoku(100%)
Audio Recorder
Tap the red button to start. Tap again to stop and save.
🎵 Saving as audio file (recommended)
Ready
00:00
0
Sci
SECURITY REVIEW TEST VERSION · BIG SUDOKU 20-MIN SCREEN-ON
보안 심사 테스트 버전 · 빅 스도쿠 20분 화면 켜짐
TIME LEFT / 남은 시간
20:00
CHARACTER / 캐릭터
👨
SCORE / 점수
100
MISTAKES / 오답
0
AI
0

How to Play Big Sudoku / 빅 스도쿠 게임 방법

English: Choose a character, then fill empty cells with numbers from 1 to 16. Correct answers keep your score. Wrong answers deduct your character penalty. If your score reaches 0, restart Big Sudoku. A no-mistake clear within the selected duration enters the Hall of Fame.

한국어: 캐릭터를 고른 뒤 빈칸에 1부터 16까지의 숫자를 입력하세요. 정답은 점수를 유지하고, 오답은 캐릭터별 벌점만큼 감점됩니다. 0점이 되면 빅 스도쿠를 다시 시작해야 합니다. 선택한 시간 안에 무오답으로 클리어하면 명예의 전당에 기록됩니다.

Select an empty cell and choose a number. / 빈칸을 선택하고 숫자를 고르세요.

🏆 Hall of Fame / 명예의 전당

No records yet. / 아직 기록이 없습니다.

⚙ Settings

💾 Save Format (most important)
Choose how recordings are saved. Default is "as-is" so the file plays normally. The image option keeps the audio bytes unchanged but saves the file with a .jpg extension; rename it to .webm to play it back.
📖 Why was this built? — Open Design Philosophy
Read the design rationale, security reasoning, and field-safety warnings.
🔒 Hide Settings Icon
Tap to remove the ⚙ icon. To reset settings to initial defaults: switch to the calculator, type 0000 (or your changed code), then press =. To start/stop recording in calculator mode: type 0000 (or your changed code), then press ×. The code is changeable below.
Default Screen
Default screen on launch
Choose what appears when the app opens. You can also switch via the toggle at the top of the recorder screen.
▣ Compact Visible Mode
For Samsung pop-up or split-screen review testing. In calculator mode, type 0000 (or your changed code), then press %. The app cannot turn itself into a Samsung pop-up window; open pop-up view manually from Android Recents.
Compact visible mode
Keeps a small visible recorder surface. Use only while the PWA window remains visible.
UI transparency 0%
☀ Review recording duration
Choose the Big Sudoku review recording duration. This does not change Android system screen-timeout settings; the app only attempts to keep the screen awake through Wake Lock while it remains visible.
Duration
Recording Trigger
Instant recording on launch
Auto-record the moment the app opens. In calculator mode, recording is fully silent.
Voice keyword trigger
Auto-record on keyword detection (high battery use).
Acoustic event auto-record
Auto-record on gunshots / explosions / screams via amplitude analysis.
BLE external trigger
Auto-record on danger signal from VitalGuard mesh.
Storage Behavior
Automatic chunk splitting
Split every 30s; one file seizure ≠ full exposure.
Screen-off recording
Tries to keep the screen awake while recording; cannot guarantee recording after the device is locked.
VAD silence compression
Detect speech regions; useful for analysis (does not modify the saved file).
Emergency
Panic wipe (3-tap)
Top-left corner × 3 rapid taps → clear app settings/cache. Downloaded files cannot be deleted by this web app.
License
© 2026 Morgan J. (Gyu-min Jeon) | M-Corp Ethical AI
M-Corp Ethical AI License (Hippocratic 3.0 Derivative)
Civilian / agricultural / humanitarian purposes only
contact@mcorpai.org · mcorpai.org

📖 Why was this built? / 왜 이렇게 만들었는가?

⚠ REVIEW STATUS — READ FIRST

This file is a security-review demonstrator. It is not a public release, not a consumer app, and not intended for distribution.

The PWA recorder is used to demonstrate offline, single-file, zero-dependency recording patterns and their browser-level limits. It should be evaluated as a review artifact, not as a deployed field application.

Calculator camouflage, Compact Visible Mode, and image-extension saving are reviewable design patterns. They do not remove platform limits, legal obligations, or device-level indicators controlled by Android or the browser.

💾 About the Save Format option (V3.0)

Earlier versions tried to disguise files by altering the header. V3.8 keeps the safer two-option model:

  • As-is (default): The recording is saved unmodified. It plays directly in any audio player. Use this when you simply want a normal recording file.
  • Image extension disguise: The audio bytes are preserved unchanged, but the file is downloaded with a .jpg extension. It may appear as a broken image. To play the audio, manually rename IMG_20260105_xxx.jpg back to .webm. Because the audio bytes are not wrapped or padded, renaming restores playback.

You can change this option at any time. It only affects future recordings, not files already saved.

The two-screen model

The app has two distinct screens:

  • Recorder screen: Normal UX. Toasts, dialogs, and the help button work here. Default on first launch.
  • Calculator screen: A working scientific calculator. The app is absolutely silent here — no toasts, no dialogs, no recording indicator, no help. Even when recording is active, the screen behaves like a normal calculator. This is the operational mode for risky environments.

Switch between them using the toggle at the top of the recorder screen.

▣ Compact Visible Mode (V3.8)

Compact Visible Mode creates a very small recorder surface intended for Samsung pop-up view or split-screen review testing. It does not make the web app a true Android background recorder.

  • Calculator command: type 0000 (or your changed code), then press %.
  • Transparency: Settings allow 0%–100% UI transparency. 0% means fully opaque; 100% means fully transparent. This controls only the web UI surface, not the Android pop-up window frame.
  • Samsung pop-up: the PWA cannot switch itself into Samsung pop-up view. Open Android Recents manually and choose pop-up or split-screen view.
  • Reliability: recording is most likely to continue while the PWA window remains visibly open. If the app is fully hidden, minimized, or the screen locks, recording is not guaranteed.

Recommended S23 test flow: start recording, enter 0000 + % for Compact Visible Mode, open Samsung pop-up view from Android Recents, set the screen-on review duration to 20/60 minutes, keep the device charging if possible, then verify saved files after 5, 20, and 60 minutes.

Hidden gear icon

The ⚙ icon can be hidden so the app appears to be only a calculator. To reset settings to the initial default state: switch to the calculator screen, type 0000 (or your changed code), then press =. The reset uses the current code; after reset, the code returns to 0000.

To start or stop recording from the calculator screen: type 0000 (or your changed code), then press ×. Recording remains silent in calculator mode.

To enter Compact Visible Mode from the calculator screen: type 0000 (or your changed code), then press %.

If you enter the wrong code, press C. The C key clears both the visible calculator expression and the hidden command buffer. For example, if you accidentally enter 000 instead of 0000, press C and start again.

If you tap "Hide" from the recorder screen, the app first switches to the calculator and then removes the gear icon. Use the keypad commands above to record or reset settings.

Why no password at recording time?

Earlier versions required a password before each recording. Field testing showed this fails the most basic field reality: in an emergency, every second of fumbling with a password creates risk. V3.0 removes the password barrier. Recording starts the instant the user taps. Encryption can be added at the storage layer in production builds without blocking the capture path.

Single HTML file, zero dependencies

VitalGuard's core philosophy: auditable single file = supply chain attack immunity. Zero external libraries, CDNs, or API calls — only one SHA-256 hash needs verification. Service Worker and Manifest are inlined via data: URLs.

Acoustic / keyword / BLE triggers

Gunshots, explosions, and screams produce clear amplitude spikes (100–120 dB). The Web Audio API's AnalyserNode computes RMS and Zero-Crossing Rate; recording auto-starts when thresholds are exceeded. Pure DSP — no external ML.

When triggered while the calculator screen is active, recording starts silently — no toast, no indicator. Evidence is preserved without exposing the user.

Panic wipe (3-tap)

Three rapid taps within 1 second on the invisible top-left zone stops any active recording and clears this app's local settings/cache. Browser security prevents a web app from deleting files that were already downloaded to the device's file system.

Use the device file manager to remove downloaded recording files if needed.

GDPR · UNCRC · CRPD alignment by design

  • GDPR: zero servers → zero data transfer → zero processor liability
  • UNCRC: child-protection alerts without any data collection
  • CRPD: simple UI usable by non-specialists

Compliance is structural, not bolted on.

Pre-deployment status

This is a demonstrator. Production deployment will add independent security audit (ROS), multilingual UI (Arabic, Rohingya, etc.), field pilots (UCL GDI Hub, IDS Sussex), Hippocratic License 3.0 liability clauses, and optional storage-layer AES-256-GCM that does not block the capture path.