Gallery Safe do not change files on phone disk.
Just import your private secret files from built-in phone gallery to Gallery Safe vault.
All files inside Gallery Safe are secured with military grade encryption AES 256.

Gallery Safe is password protected.
Gallery Safe is auto locking after selected interval of time of inactivity.

You can hide any type of files to gallery vault.
Gallery Safe have built-in viewer for photo, pictures, GIF, video, audio.
Share encrypted pictures with friend who has Gallery Safe.

You can make photo right to gallery.
You can create encrypted Backups of Gallery Safe files.
Gallery has ANY LEVEL folder album hierarchy.

Easy import and export files from (to) Gallery.
Gallery has handy Picture zoom.

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.