Apps like this have been around for several years but I wasn’t aware of them until this morning when a friend told me about Calculator Vault. Looks just like the Calculator app that comes with iOS but when you put in a secret sequence of numbers and symbols, it takes you to hidden folders where you can safely store those naughty photos. Apps like these became popular, I’m told, when teens started Snapchatting.

The Fake PIN features creates “a second PIN that opens a decoy KeepSafe for times when someone pressures you to open your KeepSafe. You can even put photos in your fake KeepSafe that are ok for others to see.”

The Secret Door feature will “masquerade your KeepSafe as another app. With Secret Door enabled, others will see what appears like another app when they open KeepSafe, but you will know the secret to reveal the PIN pad and open your KeepSafe.”

I’m told the only way you’d see these hidden folders — assuming you were looking — is from within the app. Yes, the NSA probably knows about these but your mom might not. You should tell her before she gets busted.