How to Lock Apps So No One Can Guess or Watch Your Password

How app locks are actually defeated

• Observation: digits and patterns are easy to memorise from a glance.
• Guessing: birthdays, 0000, 1234, the L-shaped pattern.
• Smudges: a swipe pattern leaves a trail on the glass.
• Uninstalling the lock app or force-stopping it.
• Shared biometrics on family phones.

Make the password invisible

Picture AppLock uses three secret spots on a photo of your choosing. There is no keypad to watch and no pattern to trace, and an onlooker cannot tell which of the thousands of points on the image you touched. Set the match accuracy to high and random taps have practically no chance.

1. Choose a detailed photo and three memorable but non-obvious spots.
2. Set match accuracy to a small radius.
3. Enable uninstall protection so the lock cannot be removed without your code.
4. Enable biometric recovery so you are never locked out.

Habits that close the remaining gaps

• Lock the phone itself with a strong code; an app lock is a second layer.
• Set the lock to engage immediately after leaving an app.
• Hide notification content for the apps you lock.
• Do not reuse your phone PIN as any app's PIN.

Why this is safer than it sounds

Three tap locations on an image, each with a small tolerance, give a search space far larger than a four-digit PIN, and the photo gives no hint which points matter. Combined with uninstall protection and the fact that the photo and coordinates never leave the device, it is both harder to break and harder to shoulder-surf than the usual keypad.