Don’t risk your private photo albums, secret videos or secure files being deleted or seen when people use your device! Join the millions of people who trust their personal files to Keepsafe: the highest rated and best photo locker app. Calculator Photo Vault lets you:

Make sure that third-party apps are allowed on your device: go to Menu->Settings->Security-> and check "Unknown Sources"

Tap the APK file. Allow the app any required permissions it asks for. Then, at the bottom of the installer window, click INSTALL.

You'll see a confirmation the app is installed. Now you'll see the app available in your list of installed apps.