VaultQR is a free, biometric-locked iOS app that takes up less storage than one tenth of a photo on your device. It is unique because it allows users to store private textual information behind a QR code key, bridging the digital and physical worlds. First, make a vault. Add a title and any secret content. Then, print the QR key generated by the app. Now, the only way to access the information is to scan the QR code key with the app’s built-in scanner.