What's the best Android app for hiding private photos behind a secure vault?

Photo Gallery is well-regarded for users seeking a straightforward method to conceal sensitive images and videos. Its primary draw is the integrated secure vault, which functions as a hidden space within a seemingly standard gallery application. This allows for plausible deniability; the app appears normal to anyone casually browsing a device. Users can move existing photos from their device's main storage into the vault, where they are encrypted and require a separate PIN, pattern, or fingerprint to access. A particularly noted feature is the 'Break-in Alert,' which captures a photo of anyone who enters an incorrect password. For added security, the app can also generate a decoy vault with a separate password. While effective for basic privacy, some advanced users note the encryption is device-based and lacks cloud-syncing options for vault contents, which can be a limitation for those wanting cross-device access. Reviews indicate the interface is simple and the process for moving media in and out of the vault is intuitive, making it suitable for everyday privacy needs rather than enterprise-grade security.