Features
Each feature below is implemented in the app. Cross-app locking is Android-only and best-effort by platform design.
Pick any launchable app from a searchable list and lock it.
How: A foreground service reads the foreground app via UsageStatsManager and launches a native lock screen over locked apps.
Privacy: App list is read locally only; nothing is uploaded.
A numeric PIN (6+ digits) unlocks Open Lock and your locked apps.
How: Only a salted PBKDF2-HMAC-SHA256 verifier is stored — never the raw PIN. Repeated wrong entries trigger an escalating cooldown.
Security: The same verifier is checked identically in Dart and native Kotlin, fully offline.
Use your fingerprint or face where available.
How: AndroidX BiometricPrompt (strong/weak) on the lock screen, with the PIN pad always available as a fallback.
Note: The PIN remains the source of truth; biometrics are a convenience gate.
Choose when an unlocked app relocks.
Options: the moment you leave, after 1 / 5 / 15 / 30 minutes, or when the screen turns off. A reboot always relocks everything.
Lock a chosen set of apps during time windows.
How: Per-weekday windows — same-day, overnight, or all-day — enforced by the background guard on the local clock.
Automatically lock apps installed later.
How: When enabled, the monitor listens for package-install events and adds newly installed apps to the locked set.
Record failed-unlock attempts, optionally with a photo.
How: After a configurable number of wrong attempts, Open Lock can silently take a front-camera photo and log the time and app.
Privacy: Photos are stored in app-private storage and can be deleted anytime.
Shuffle the keypad digits to foil shoulder-surfers.
How: An optional setting randomizes digit positions on the lock screen.
Show a fake "app has stopped" dialog instead of a lock screen.
How: When enabled, a decoy is shown; a long-press reveals the real unlock screen.
Make Open Lock harder to remove.
How: Optional Android device-administrator status blocks the normal uninstall flow; turning it off is auth-gated with your PIN or fingerprint.
Honest limit: A determined user with ADB, Safe Mode, or a factory reset can still remove any non-system app.
Export and import your configuration.
How: .olbackup files are encrypted with AES-256-GCM under an Argon2id key derived from a passphrase you choose (separate from your PIN).
Protection resumes after a reboot; optional update checks.
How: A boot receiver restarts the guard after a restart. An optional in-app check looks for newer releases on GitHub (toggleable in Settings).
