Night Lock: Auto-Lock Privacy

Everyone forgets their phone sometimes. Night Lock doesn't.

Fell asleep mid-scroll. Got distracted and left it on the couch. Walked away from your desk with the screen still on. That's all it takes for someone to go through your messages, photos, and accounts — no hacking required, just your unlocked phone and thirty seconds.

Night Lock closes that door.

⏰ Pick your guard hours — or guard around the clock.
Overnight while you sleep, evenings when the house is busy, work hours at the shop — you choose when the watch is on duty. At your chosen start time, Night Lock locks the screen automatically, even if a video is keeping it awake.

🔑 One secret passphrase stands between your phone and everyone else.
During guard hours, every unlock gets challenged: enter your passphrase or the phone re-locks in seconds. Sneaking around the prompt — Home button, switching apps, anything — locks it instantly. Five wrong guesses? Locked.

😴 Distracted after unlocking? Still covered.
Enter your passphrase and use the phone normally — every touch keeps it awake to you. But 60 seconds without a touch, whether you dozed off or wandered to the kitchen, and it locks itself again.

🛡️ Private by design — we can't see anything.
• No accounts. No ads. No tracking. No analytics. Nothing to sell, because we collect nothing.
• Everything happens on your phone. There is no server, no cloud, no "us."

🔐 For the security-minded — the actual details:
• Your passphrase is never stored. On setup, the app generates a random 16-byte salt (SecureRandom) and derives a PBKDF2-HMAC-SHA256 hash at 600,000 iterations — the OWASP-recommended strength. Only that hash is kept, in Android's app-private sandboxed storage, and compared in constant time. One-way math: it can be checked, never recovered.
• Backups excluded (allowBackup=false) — the hash never leaves the device, not even in Google backups.
• Zero network capability. Not "we don't send data" — the manifest contains no INTERNET permission at all. Decompile it and check; we hope you do.
• No third-party SDKs, no analytics libraries, no frameworks. Pure Android APIs, and the entire app is about 25 KB.
• Wrong-guess lockout: 5 failed attempts locks the device on the spot.

⚙️ Simple setup, three permissions, all explained:
• Device admin (screen lock) — lets Night Lock actually lock the screen. It cannot read your data, wipe your phone, or see your PIN.
• Display over other apps — lets the passphrase prompt appear on top of whatever's open.
• Notifications — a quiet status note while the watch is on duty.

Made for:
• Anyone who falls asleep scrolling
• The easily distracted — phone on the counter, screen still on
• Shared apartments, dorms, and nosy households
• Travel: hostels, red-eyes, hotel nightstands
• Parents whose kids go phone-fishing after bedtime

Outside your guard hours, Night Lock stays completely invisible. Your phone, your schedule.

For every time you forgot to lock it — it didn't.