Oceanic Calculator Vault is an app that has the interface of a Calculator and it has a hidden vault. The vault can be accessed only by typing the pin followed by activation button where pin can be numbers and mathematical symbols.

The main features which make it different and secure from any other similar is that it uses blockchain technology to encrypt your photos and thus will not be available to anyone unless using the app with correct pin followed by activation number. Even if the phone is rooted, no hidden photos can be revealed. This is the most secure app which can store your private files in your phone even if your phone's password is known to someone.
Another feature is that after you install the app, the name of the app will be "Oceanic Calculator" instead of "Oceanic Calculator Vault" and hence no one will be able to identify it.